All Lecture 231

lecture 02

set working directory

# "D:/2nd Year/AST 231" replace '/' by '\\' 
setwd("D:\\2nd Year\\AST 231\\AST 231")
# or, Session >set working directory > to source file location
setwd("D:/2nd Year/AST 231/AST 231")

read excel file

data<-read.csv("D:\\2nd Year\\AST 231\\AST 231\\EXCELL PRACTICE.csv")
View(data)
income <- read.table("D:/2nd Year/AST 231/EXCELL PRACTICE.csv", header=T)
View(income)

data2<-read.dta(““) data3<-read.spss(”“) data4<-read.table(”“,header = FALSE) data5<-read.csv(”“)

head(data1)

for build in R data

library("foreign")
data("mtcars")
mtcars
##                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
## Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
## Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
## Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
## Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
## Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
## Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
## Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
## Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
## Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
## Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
## Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
## Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
## Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
## Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
## Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
## Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
## Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
## Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
## Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
## AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
## Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
## Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
## Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
## Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
## Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
## Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
## Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
## Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
## Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2
data("iris")
iris
##     Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
## 1            5.1         3.5          1.4         0.2     setosa
## 2            4.9         3.0          1.4         0.2     setosa
## 3            4.7         3.2          1.3         0.2     setosa
## 4            4.6         3.1          1.5         0.2     setosa
## 5            5.0         3.6          1.4         0.2     setosa
## 6            5.4         3.9          1.7         0.4     setosa
## 7            4.6         3.4          1.4         0.3     setosa
## 8            5.0         3.4          1.5         0.2     setosa
## 9            4.4         2.9          1.4         0.2     setosa
## 10           4.9         3.1          1.5         0.1     setosa
## 11           5.4         3.7          1.5         0.2     setosa
## 12           4.8         3.4          1.6         0.2     setosa
## 13           4.8         3.0          1.4         0.1     setosa
## 14           4.3         3.0          1.1         0.1     setosa
## 15           5.8         4.0          1.2         0.2     setosa
## 16           5.7         4.4          1.5         0.4     setosa
## 17           5.4         3.9          1.3         0.4     setosa
## 18           5.1         3.5          1.4         0.3     setosa
## 19           5.7         3.8          1.7         0.3     setosa
## 20           5.1         3.8          1.5         0.3     setosa
## 21           5.4         3.4          1.7         0.2     setosa
## 22           5.1         3.7          1.5         0.4     setosa
## 23           4.6         3.6          1.0         0.2     setosa
## 24           5.1         3.3          1.7         0.5     setosa
## 25           4.8         3.4          1.9         0.2     setosa
## 26           5.0         3.0          1.6         0.2     setosa
## 27           5.0         3.4          1.6         0.4     setosa
## 28           5.2         3.5          1.5         0.2     setosa
## 29           5.2         3.4          1.4         0.2     setosa
## 30           4.7         3.2          1.6         0.2     setosa
## 31           4.8         3.1          1.6         0.2     setosa
## 32           5.4         3.4          1.5         0.4     setosa
## 33           5.2         4.1          1.5         0.1     setosa
## 34           5.5         4.2          1.4         0.2     setosa
## 35           4.9         3.1          1.5         0.2     setosa
## 36           5.0         3.2          1.2         0.2     setosa
## 37           5.5         3.5          1.3         0.2     setosa
## 38           4.9         3.6          1.4         0.1     setosa
## 39           4.4         3.0          1.3         0.2     setosa
## 40           5.1         3.4          1.5         0.2     setosa
## 41           5.0         3.5          1.3         0.3     setosa
## 42           4.5         2.3          1.3         0.3     setosa
## 43           4.4         3.2          1.3         0.2     setosa
## 44           5.0         3.5          1.6         0.6     setosa
## 45           5.1         3.8          1.9         0.4     setosa
## 46           4.8         3.0          1.4         0.3     setosa
## 47           5.1         3.8          1.6         0.2     setosa
## 48           4.6         3.2          1.4         0.2     setosa
## 49           5.3         3.7          1.5         0.2     setosa
## 50           5.0         3.3          1.4         0.2     setosa
## 51           7.0         3.2          4.7         1.4 versicolor
## 52           6.4         3.2          4.5         1.5 versicolor
## 53           6.9         3.1          4.9         1.5 versicolor
## 54           5.5         2.3          4.0         1.3 versicolor
## 55           6.5         2.8          4.6         1.5 versicolor
## 56           5.7         2.8          4.5         1.3 versicolor
## 57           6.3         3.3          4.7         1.6 versicolor
## 58           4.9         2.4          3.3         1.0 versicolor
## 59           6.6         2.9          4.6         1.3 versicolor
## 60           5.2         2.7          3.9         1.4 versicolor
## 61           5.0         2.0          3.5         1.0 versicolor
## 62           5.9         3.0          4.2         1.5 versicolor
## 63           6.0         2.2          4.0         1.0 versicolor
## 64           6.1         2.9          4.7         1.4 versicolor
## 65           5.6         2.9          3.6         1.3 versicolor
## 66           6.7         3.1          4.4         1.4 versicolor
## 67           5.6         3.0          4.5         1.5 versicolor
## 68           5.8         2.7          4.1         1.0 versicolor
## 69           6.2         2.2          4.5         1.5 versicolor
## 70           5.6         2.5          3.9         1.1 versicolor
## 71           5.9         3.2          4.8         1.8 versicolor
## 72           6.1         2.8          4.0         1.3 versicolor
## 73           6.3         2.5          4.9         1.5 versicolor
## 74           6.1         2.8          4.7         1.2 versicolor
## 75           6.4         2.9          4.3         1.3 versicolor
## 76           6.6         3.0          4.4         1.4 versicolor
## 77           6.8         2.8          4.8         1.4 versicolor
## 78           6.7         3.0          5.0         1.7 versicolor
## 79           6.0         2.9          4.5         1.5 versicolor
## 80           5.7         2.6          3.5         1.0 versicolor
## 81           5.5         2.4          3.8         1.1 versicolor
## 82           5.5         2.4          3.7         1.0 versicolor
## 83           5.8         2.7          3.9         1.2 versicolor
## 84           6.0         2.7          5.1         1.6 versicolor
## 85           5.4         3.0          4.5         1.5 versicolor
## 86           6.0         3.4          4.5         1.6 versicolor
## 87           6.7         3.1          4.7         1.5 versicolor
## 88           6.3         2.3          4.4         1.3 versicolor
## 89           5.6         3.0          4.1         1.3 versicolor
## 90           5.5         2.5          4.0         1.3 versicolor
## 91           5.5         2.6          4.4         1.2 versicolor
## 92           6.1         3.0          4.6         1.4 versicolor
## 93           5.8         2.6          4.0         1.2 versicolor
## 94           5.0         2.3          3.3         1.0 versicolor
## 95           5.6         2.7          4.2         1.3 versicolor
## 96           5.7         3.0          4.2         1.2 versicolor
## 97           5.7         2.9          4.2         1.3 versicolor
## 98           6.2         2.9          4.3         1.3 versicolor
## 99           5.1         2.5          3.0         1.1 versicolor
## 100          5.7         2.8          4.1         1.3 versicolor
## 101          6.3         3.3          6.0         2.5  virginica
## 102          5.8         2.7          5.1         1.9  virginica
## 103          7.1         3.0          5.9         2.1  virginica
## 104          6.3         2.9          5.6         1.8  virginica
## 105          6.5         3.0          5.8         2.2  virginica
## 106          7.6         3.0          6.6         2.1  virginica
## 107          4.9         2.5          4.5         1.7  virginica
## 108          7.3         2.9          6.3         1.8  virginica
## 109          6.7         2.5          5.8         1.8  virginica
## 110          7.2         3.6          6.1         2.5  virginica
## 111          6.5         3.2          5.1         2.0  virginica
## 112          6.4         2.7          5.3         1.9  virginica
## 113          6.8         3.0          5.5         2.1  virginica
## 114          5.7         2.5          5.0         2.0  virginica
## 115          5.8         2.8          5.1         2.4  virginica
## 116          6.4         3.2          5.3         2.3  virginica
## 117          6.5         3.0          5.5         1.8  virginica
## 118          7.7         3.8          6.7         2.2  virginica
## 119          7.7         2.6          6.9         2.3  virginica
## 120          6.0         2.2          5.0         1.5  virginica
## 121          6.9         3.2          5.7         2.3  virginica
## 122          5.6         2.8          4.9         2.0  virginica
## 123          7.7         2.8          6.7         2.0  virginica
## 124          6.3         2.7          4.9         1.8  virginica
## 125          6.7         3.3          5.7         2.1  virginica
## 126          7.2         3.2          6.0         1.8  virginica
## 127          6.2         2.8          4.8         1.8  virginica
## 128          6.1         3.0          4.9         1.8  virginica
## 129          6.4         2.8          5.6         2.1  virginica
## 130          7.2         3.0          5.8         1.6  virginica
## 131          7.4         2.8          6.1         1.9  virginica
## 132          7.9         3.8          6.4         2.0  virginica
## 133          6.4         2.8          5.6         2.2  virginica
## 134          6.3         2.8          5.1         1.5  virginica
## 135          6.1         2.6          5.6         1.4  virginica
## 136          7.7         3.0          6.1         2.3  virginica
## 137          6.3         3.4          5.6         2.4  virginica
## 138          6.4         3.1          5.5         1.8  virginica
## 139          6.0         3.0          4.8         1.8  virginica
## 140          6.9         3.1          5.4         2.1  virginica
## 141          6.7         3.1          5.6         2.4  virginica
## 142          6.9         3.1          5.1         2.3  virginica
## 143          5.8         2.7          5.1         1.9  virginica
## 144          6.8         3.2          5.9         2.3  virginica
## 145          6.7         3.3          5.7         2.5  virginica
## 146          6.7         3.0          5.2         2.3  virginica
## 147          6.3         2.5          5.0         1.9  virginica
## 148          6.5         3.0          5.2         2.0  virginica
## 149          6.2         3.4          5.4         2.3  virginica
## 150          5.9         3.0          5.1         1.8  virginica

random number genarate

set.seed(13)
x1<-rnorm(n=10,mean=10,sd =4)
x1
##  [1] 12.217308  8.878912 17.100653 10.749280 14.570105 11.662105 14.918026
##  [8] 10.946719  8.538469 14.420577
rbinom(n = 5,size = 1,prob = .5)
## [1] 0 1 1 1 0
rweibull(n = 6,shape = 5,scale = 6)
## [1] 5.176618 7.686552 5.699531 6.125001 5.128995 5.821886

lecture 03

calculate probability distribution (pdf)

dbinom(x=2,size=10,prob=.6)
## [1] 0.01061683

lecture 04

Example (cdf)

calculate p(1<X<=3)

#p(x<=3)
p3<-pbinom(q = 3,size = 10,prob = 0.6,lower.tail = T)
p3
## [1] 0.05476188
#p(x<=1)
p1<-pbinom(q = 1,size = 10,prob = 0.6,lower.tail = TRUE)
p1
## [1] 0.001677722
#p(1<X<=3)
p<-p3-p1
p
## [1] 0.05308416

with replacement sample

X=3,6,7,10,12 p=.1,.3,.2,.2,.2 draw 3 sample each time

a<-c(3,6,7,10,12)
p<-c(.1,.3,.2,.2,.2)

sample(x = a,size = 3,prob =p,replace = TRUE)
## [1]  7  3 12

without replacement sample

X=3,6,7,10,12 p=.1,.3,.2,.2,.2 draw 3 sample each time

a<-c(3,6,7,10,12)
p<-c(.1,.3,.2,.2,.2)
sample(x = a,size = 3,prob =p,replace = FALSE)
## [1] 10  6 12
set.seed(13)
s1<-sample(x = a,size = 500,prob =p,replace = TRUE)
mean(s1)
## [1] 7.818
var(s1)
## [1] 7.720317
# main for histogram title
hist(s1,main = "500 discrete draws")

lecture 05

Distribution of sample statistic

Find the distribution of mean & variance by drawing 100 sized sample from N(4,10) 1000 times

y<-rnorm(n = 100,mean = 4,sd = sqrt(10))
y
##   [1]  5.94095626  5.30480169  2.54885080  1.87122266  4.61049129  8.37320566
##   [7]  4.20544476 11.28033382 -2.58916772  0.34077286  5.97264666 -0.81570326
##  [13] -4.25688404 11.98972795  5.19499480  4.08995613  1.76734170  6.00741276
##  [19]  7.69615887  3.02544085  1.77444953 -0.01607200  4.30224095  2.58782506
##  [25] -1.40553936 -0.56071026  8.02611207  6.42184564  1.05783075  8.57910426
##  [31]  2.37937416 11.38726222  6.07043166  3.55919294  2.40626779  4.18114778
##  [37] -0.55329936  7.96817037  5.32811829  4.33508152  4.28438528 -3.52971177
##  [43] 13.18859404  4.81202635  4.49419261 -0.06325470  2.58140991 -1.02677180
##  [49]  0.02812929  3.66213085 -0.03137001  0.50945677  4.42764435  5.05412192
##  [55]  0.71627485  4.69479016  5.25635014  8.61550432  0.31991258 -0.28487939
##  [61]  7.39083076  7.38364497  3.47262499  7.52295955 -3.05692168  9.00954065
##  [67]  0.54797634  5.50822404  5.05891439  4.52457307  5.07013784  6.06685399
##  [73]  1.14483089  3.90957473  1.69709805  3.57744188  6.49235527  1.09596700
##  [79]  8.27527031  5.77492594  8.18114451  7.01765112  6.77193608  6.15564925
##  [85]  5.37052374  8.83560748 -2.53471118  6.77609417  8.53180195  4.30523765
##  [91] -3.33215231  2.54383781  0.78827961  1.02200100  8.34790807  4.44940409
##  [97]  5.50028130 -0.68467894  8.77848863  4.33078519
m<-NULL
n<-NULL

for(i in 1:1000){
  y<-rnorm(n = 100,mean = 4,sd = sqrt(10))
  m[i]<-mean(y)
  n[i]<-var(y)
}
hist(m)

hist(n)

N~(10,0.6) find the distribution of getting success,(p)

p<-NULL
for(i in 1:1000){
  y<-rbinom(n = 100,size = 10,prob = 0.6)
  m<-mean(y)
  #note: mean=n*p or,p=mean/n
  p[i]<-m/10
  
}
p
##    [1] 0.614 0.617 0.608 0.634 0.628 0.577 0.582 0.591 0.598 0.599 0.587 0.566
##   [13] 0.594 0.603 0.613 0.616 0.597 0.577 0.595 0.615 0.596 0.594 0.604 0.580
##   [25] 0.631 0.628 0.586 0.603 0.618 0.610 0.576 0.595 0.629 0.590 0.610 0.592
##   [37] 0.615 0.581 0.582 0.590 0.583 0.633 0.599 0.622 0.587 0.616 0.595 0.621
##   [49] 0.611 0.585 0.587 0.586 0.598 0.587 0.593 0.589 0.600 0.611 0.598 0.613
##   [61] 0.594 0.590 0.599 0.595 0.581 0.595 0.583 0.599 0.628 0.613 0.613 0.602
##   [73] 0.598 0.624 0.598 0.594 0.603 0.573 0.592 0.629 0.588 0.609 0.586 0.589
##   [85] 0.582 0.566 0.595 0.594 0.576 0.598 0.614 0.598 0.601 0.585 0.605 0.616
##   [97] 0.591 0.590 0.585 0.608 0.568 0.590 0.581 0.608 0.591 0.603 0.606 0.598
##  [109] 0.600 0.604 0.591 0.596 0.615 0.580 0.586 0.594 0.616 0.627 0.606 0.578
##  [121] 0.571 0.592 0.628 0.601 0.604 0.594 0.598 0.597 0.593 0.627 0.599 0.601
##  [133] 0.605 0.602 0.584 0.622 0.606 0.627 0.593 0.591 0.601 0.591 0.595 0.611
##  [145] 0.595 0.616 0.591 0.579 0.629 0.621 0.624 0.578 0.600 0.605 0.610 0.585
##  [157] 0.591 0.593 0.606 0.584 0.574 0.572 0.615 0.597 0.619 0.578 0.582 0.597
##  [169] 0.618 0.599 0.604 0.599 0.607 0.616 0.601 0.597 0.646 0.596 0.606 0.587
##  [181] 0.592 0.608 0.628 0.601 0.598 0.584 0.598 0.613 0.589 0.584 0.568 0.592
##  [193] 0.578 0.623 0.584 0.620 0.563 0.584 0.605 0.586 0.574 0.611 0.598 0.611
##  [205] 0.633 0.602 0.583 0.595 0.633 0.607 0.598 0.600 0.614 0.601 0.590 0.571
##  [217] 0.606 0.615 0.610 0.610 0.563 0.613 0.596 0.594 0.590 0.598 0.604 0.596
##  [229] 0.606 0.583 0.586 0.598 0.585 0.590 0.604 0.632 0.604 0.601 0.565 0.608
##  [241] 0.597 0.590 0.623 0.591 0.605 0.636 0.609 0.621 0.588 0.576 0.595 0.611
##  [253] 0.582 0.578 0.636 0.590 0.612 0.580 0.610 0.600 0.596 0.605 0.598 0.578
##  [265] 0.594 0.596 0.581 0.602 0.594 0.610 0.576 0.584 0.595 0.609 0.606 0.620
##  [277] 0.606 0.584 0.564 0.598 0.566 0.584 0.606 0.605 0.590 0.607 0.601 0.599
##  [289] 0.575 0.596 0.594 0.606 0.606 0.616 0.611 0.594 0.590 0.606 0.615 0.629
##  [301] 0.581 0.567 0.589 0.616 0.578 0.565 0.584 0.578 0.584 0.608 0.579 0.589
##  [313] 0.589 0.618 0.617 0.590 0.606 0.621 0.610 0.594 0.599 0.590 0.603 0.618
##  [325] 0.598 0.614 0.605 0.581 0.591 0.590 0.567 0.604 0.606 0.603 0.575 0.589
##  [337] 0.609 0.597 0.602 0.617 0.598 0.580 0.620 0.618 0.593 0.601 0.580 0.613
##  [349] 0.615 0.616 0.614 0.636 0.639 0.582 0.603 0.616 0.594 0.597 0.561 0.578
##  [361] 0.630 0.588 0.625 0.605 0.613 0.589 0.596 0.586 0.597 0.599 0.589 0.590
##  [373] 0.610 0.568 0.616 0.633 0.615 0.578 0.614 0.603 0.596 0.587 0.592 0.611
##  [385] 0.597 0.619 0.602 0.596 0.618 0.594 0.583 0.621 0.589 0.608 0.600 0.633
##  [397] 0.597 0.616 0.624 0.584 0.616 0.625 0.595 0.570 0.592 0.605 0.578 0.633
##  [409] 0.614 0.586 0.601 0.589 0.588 0.606 0.604 0.597 0.575 0.598 0.606 0.609
##  [421] 0.584 0.630 0.596 0.586 0.576 0.609 0.627 0.626 0.577 0.610 0.601 0.640
##  [433] 0.578 0.604 0.569 0.590 0.604 0.611 0.581 0.576 0.599 0.596 0.585 0.574
##  [445] 0.586 0.606 0.597 0.601 0.618 0.603 0.590 0.600 0.606 0.598 0.596 0.622
##  [457] 0.582 0.599 0.617 0.590 0.598 0.607 0.609 0.595 0.596 0.592 0.603 0.601
##  [469] 0.608 0.595 0.609 0.590 0.582 0.585 0.602 0.567 0.593 0.628 0.602 0.620
##  [481] 0.622 0.596 0.597 0.593 0.611 0.594 0.595 0.609 0.612 0.578 0.597 0.602
##  [493] 0.622 0.601 0.641 0.599 0.575 0.592 0.581 0.606 0.568 0.622 0.598 0.613
##  [505] 0.614 0.577 0.581 0.581 0.596 0.590 0.596 0.614 0.610 0.616 0.614 0.594
##  [517] 0.600 0.594 0.603 0.588 0.613 0.613 0.581 0.624 0.618 0.595 0.586 0.619
##  [529] 0.647 0.591 0.606 0.595 0.594 0.580 0.591 0.581 0.622 0.590 0.599 0.574
##  [541] 0.609 0.605 0.619 0.598 0.602 0.584 0.599 0.603 0.573 0.598 0.611 0.589
##  [553] 0.565 0.616 0.642 0.613 0.644 0.606 0.602 0.613 0.606 0.626 0.604 0.585
##  [565] 0.590 0.580 0.581 0.588 0.603 0.600 0.587 0.594 0.617 0.595 0.596 0.619
##  [577] 0.619 0.609 0.599 0.607 0.586 0.610 0.599 0.592 0.632 0.584 0.580 0.613
##  [589] 0.603 0.588 0.579 0.599 0.602 0.597 0.582 0.615 0.584 0.617 0.610 0.610
##  [601] 0.588 0.573 0.580 0.589 0.589 0.580 0.595 0.606 0.584 0.593 0.591 0.592
##  [613] 0.615 0.613 0.609 0.589 0.590 0.594 0.583 0.597 0.569 0.588 0.580 0.599
##  [625] 0.595 0.618 0.593 0.613 0.630 0.593 0.589 0.626 0.602 0.616 0.582 0.584
##  [637] 0.582 0.597 0.595 0.606 0.628 0.634 0.589 0.586 0.589 0.583 0.597 0.601
##  [649] 0.610 0.606 0.608 0.635 0.622 0.593 0.606 0.593 0.601 0.600 0.598 0.626
##  [661] 0.578 0.596 0.581 0.589 0.599 0.593 0.605 0.588 0.600 0.606 0.591 0.592
##  [673] 0.625 0.617 0.619 0.609 0.611 0.591 0.592 0.564 0.601 0.599 0.611 0.606
##  [685] 0.611 0.571 0.600 0.608 0.594 0.597 0.589 0.589 0.611 0.622 0.583 0.595
##  [697] 0.639 0.590 0.589 0.601 0.603 0.609 0.581 0.587 0.602 0.607 0.625 0.600
##  [709] 0.607 0.600 0.623 0.591 0.580 0.618 0.614 0.579 0.592 0.578 0.583 0.604
##  [721] 0.591 0.596 0.598 0.595 0.620 0.604 0.607 0.605 0.582 0.599 0.600 0.616
##  [733] 0.593 0.619 0.561 0.591 0.615 0.599 0.618 0.592 0.570 0.579 0.600 0.616
##  [745] 0.558 0.586 0.587 0.602 0.578 0.609 0.592 0.602 0.602 0.603 0.617 0.567
##  [757] 0.605 0.617 0.597 0.608 0.620 0.603 0.617 0.600 0.584 0.577 0.608 0.593
##  [769] 0.617 0.615 0.612 0.572 0.600 0.588 0.607 0.605 0.574 0.583 0.597 0.602
##  [781] 0.610 0.575 0.618 0.605 0.619 0.579 0.608 0.597 0.587 0.613 0.612 0.578
##  [793] 0.585 0.592 0.591 0.635 0.628 0.604 0.592 0.586 0.598 0.585 0.596 0.598
##  [805] 0.613 0.599 0.596 0.598 0.624 0.612 0.621 0.615 0.574 0.598 0.603 0.589
##  [817] 0.605 0.586 0.611 0.578 0.561 0.558 0.613 0.599 0.598 0.588 0.609 0.587
##  [829] 0.588 0.595 0.606 0.582 0.632 0.582 0.583 0.584 0.598 0.602 0.611 0.569
##  [841] 0.631 0.613 0.581 0.596 0.568 0.586 0.596 0.614 0.615 0.605 0.601 0.582
##  [853] 0.594 0.571 0.604 0.629 0.599 0.569 0.600 0.610 0.603 0.602 0.589 0.594
##  [865] 0.614 0.597 0.588 0.624 0.602 0.589 0.564 0.607 0.575 0.609 0.589 0.580
##  [877] 0.602 0.610 0.600 0.591 0.606 0.607 0.567 0.592 0.603 0.606 0.599 0.590
##  [889] 0.553 0.609 0.617 0.591 0.593 0.610 0.579 0.593 0.602 0.566 0.599 0.592
##  [901] 0.599 0.625 0.600 0.600 0.596 0.611 0.602 0.596 0.625 0.610 0.588 0.611
##  [913] 0.624 0.592 0.595 0.594 0.601 0.574 0.606 0.601 0.627 0.608 0.612 0.607
##  [925] 0.602 0.577 0.616 0.583 0.608 0.598 0.587 0.575 0.595 0.598 0.592 0.591
##  [937] 0.618 0.595 0.588 0.589 0.598 0.609 0.613 0.595 0.619 0.585 0.575 0.604
##  [949] 0.585 0.624 0.608 0.595 0.618 0.587 0.601 0.592 0.632 0.567 0.591 0.603
##  [961] 0.582 0.588 0.594 0.596 0.574 0.604 0.589 0.604 0.595 0.583 0.608 0.579
##  [973] 0.591 0.602 0.592 0.597 0.589 0.613 0.609 0.622 0.589 0.623 0.605 0.601
##  [985] 0.614 0.611 0.597 0.597 0.590 0.593 0.591 0.602 0.590 0.616 0.618 0.574
##  [997] 0.627 0.603 0.590 0.596
hist(p)

### fairness of coin fairness of a coin (H0: coin not fair; H1: coin fair)

y<-NULL
 for (i in 1:1000){
   s<-rbinom(1000,1,0.6)
   y[i]<-sum(s)
 }
lw<-quantile(y,0.025)
lw
## 2.5% 
##  570
up<-quantile(y,0.975)
up
##   97.5% 
## 630.025
#P(H1)
p_H1<-sum (570<y & y<629)/length(y)
p_H1
## [1] 0.938
#P(H0)
p_value<-1-p_H1
p_value
## [1] 0.062

lecture 06

Generate random number

1.Draw a sample of size 200 from N (5,8) distribution.Find the percentage of sample above 6.

set.seed(13)
y<-rnorm(200,5,sqrt(8))
sum(y>6)/200*100
## [1] 35.5

simulate

2.A fair coin flipped 10 times. Simulate thisprocess 1000 times and find how many times you get an unequal number of headsand tails.

 set.seed(13)
y<-NULL
for(i in 1:1000){
  
  x<-rbinom(10,1,.5)
  y[i]<-sum(x)
}
sum(y!=5)
## [1] 751

3.Generate a sample of size 50 from poisson (10). Simulate this process 5000 times and find the probability of estimated lambda greater than 10.

set.seed(13)
y<-NULL
for(i in 1:5000){
  x<-rpois(n = 50,lambda = 10)
y[i]<-mean(x)
}
sum(y>10)/5000
## [1] 0.4846

lecture 07 (same 6)

1.Draw a sample of size 200 from N (5,8) distribution.Find the percentage of sample above 6.

set.seed(123)
y<-rnorm(200,5,sqrt(8))
sum(y>6)/200*100
## [1] 33.5

2.A fair coin flipped 10 times. Simulate this process 1000 times and find how many times you get an unequal number of heads and tails.

set.seed(12)
rbinom(n = 10,size = 1,.5)
##  [1] 0 1 1 0 0 0 0 1 0 0
y<-NULL
for(i in 1:1000){
  y[i]<-sum(rbinom(n = 10,size = 1,.5))
}
sum(y!=5)
## [1] 764

Generate a sample of size 50 from poisson (10).Simulate this process 5000 times and find the probability of estimated lambda greater than 10.

set.seed(123)
x<-NULL
  for(i in 1:5000){
    x[i]<-mean(rpois(50,10))
  }
sum(x>10)/5000
## [1] 0.493

lecture 8

UNBIASEDNESS ex-1

Unbiasedness of sample mean

# Expected Value of sample equals to parameter value
population<-c(14,12,14,17,18,19,20,21,23,24)
length(population)
## [1] 10
mean(population)
## [1] 18.2
all_sample<-combn(x = population,m = 3)
all_sample
##      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [,14]
## [1,]   14   14   14   14   14   14   14   14   14    14    14    14    14    14
## [2,]   12   12   12   12   12   12   12   12   14    14    14    14    14    14
## [3,]   14   17   18   19   20   21   23   24   17    18    19    20    21    23
##      [,15] [,16] [,17] [,18] [,19] [,20] [,21] [,22] [,23] [,24] [,25] [,26]
## [1,]    14    14    14    14    14    14    14    14    14    14    14    14
## [2,]    14    17    17    17    17    17    17    18    18    18    18    18
## [3,]    24    18    19    20    21    23    24    19    20    21    23    24
##      [,27] [,28] [,29] [,30] [,31] [,32] [,33] [,34] [,35] [,36] [,37] [,38]
## [1,]    14    14    14    14    14    14    14    14    14    14    12    12
## [2,]    19    19    19    19    20    20    20    21    21    23    14    14
## [3,]    20    21    23    24    21    23    24    23    24    24    17    18
##      [,39] [,40] [,41] [,42] [,43] [,44] [,45] [,46] [,47] [,48] [,49] [,50]
## [1,]    12    12    12    12    12    12    12    12    12    12    12    12
## [2,]    14    14    14    14    14    17    17    17    17    17    17    18
## [3,]    19    20    21    23    24    18    19    20    21    23    24    19
##      [,51] [,52] [,53] [,54] [,55] [,56] [,57] [,58] [,59] [,60] [,61] [,62]
## [1,]    12    12    12    12    12    12    12    12    12    12    12    12
## [2,]    18    18    18    18    19    19    19    19    20    20    20    21
## [3,]    20    21    23    24    20    21    23    24    21    23    24    23
##      [,63] [,64] [,65] [,66] [,67] [,68] [,69] [,70] [,71] [,72] [,73] [,74]
## [1,]    12    12    14    14    14    14    14    14    14    14    14    14
## [2,]    21    23    17    17    17    17    17    17    18    18    18    18
## [3,]    24    24    18    19    20    21    23    24    19    20    21    23
##      [,75] [,76] [,77] [,78] [,79] [,80] [,81] [,82] [,83] [,84] [,85] [,86]
## [1,]    14    14    14    14    14    14    14    14    14    14    14    17
## [2,]    18    19    19    19    19    20    20    20    21    21    23    18
## [3,]    24    20    21    23    24    21    23    24    23    24    24    19
##      [,87] [,88] [,89] [,90] [,91] [,92] [,93] [,94] [,95] [,96] [,97] [,98]
## [1,]    17    17    17    17    17    17    17    17    17    17    17    17
## [2,]    18    18    18    18    19    19    19    19    20    20    20    21
## [3,]    20    21    23    24    20    21    23    24    21    23    24    23
##      [,99] [,100] [,101] [,102] [,103] [,104] [,105] [,106] [,107] [,108]
## [1,]    17     17     18     18     18     18     18     18     18     18
## [2,]    21     23     19     19     19     19     20     20     20     21
## [3,]    24     24     20     21     23     24     21     23     24     23
##      [,109] [,110] [,111] [,112] [,113] [,114] [,115] [,116] [,117] [,118]
## [1,]     18     18     19     19     19     19     19     19     20     20
## [2,]     21     23     20     20     20     21     21     23     21     21
## [3,]     24     24     21     23     24     23     24     24     23     24
##      [,119] [,120]
## [1,]     20     21
## [2,]     23     23
## [3,]     24     24
dim(all_sample)
## [1]   3 120
all_mean<-apply(all_sample, 2, mean)
all_mean
##   [1] 13.33333 14.33333 14.66667 15.00000 15.33333 15.66667 16.33333 16.66667
##   [9] 15.00000 15.33333 15.66667 16.00000 16.33333 17.00000 17.33333 16.33333
##  [17] 16.66667 17.00000 17.33333 18.00000 18.33333 17.00000 17.33333 17.66667
##  [25] 18.33333 18.66667 17.66667 18.00000 18.66667 19.00000 18.33333 19.00000
##  [33] 19.33333 19.33333 19.66667 20.33333 14.33333 14.66667 15.00000 15.33333
##  [41] 15.66667 16.33333 16.66667 15.66667 16.00000 16.33333 16.66667 17.33333
##  [49] 17.66667 16.33333 16.66667 17.00000 17.66667 18.00000 17.00000 17.33333
##  [57] 18.00000 18.33333 17.66667 18.33333 18.66667 18.66667 19.00000 19.66667
##  [65] 16.33333 16.66667 17.00000 17.33333 18.00000 18.33333 17.00000 17.33333
##  [73] 17.66667 18.33333 18.66667 17.66667 18.00000 18.66667 19.00000 18.33333
##  [81] 19.00000 19.33333 19.33333 19.66667 20.33333 18.00000 18.33333 18.66667
##  [89] 19.33333 19.66667 18.66667 19.00000 19.66667 20.00000 19.33333 20.00000
##  [97] 20.33333 20.33333 20.66667 21.33333 19.00000 19.33333 20.00000 20.33333
## [105] 19.66667 20.33333 20.66667 20.66667 21.00000 21.66667 20.00000 20.66667
## [113] 21.00000 21.00000 21.33333 22.00000 21.33333 21.66667 22.33333 22.66667
# mean of all sample mean
mean(all_mean)
## [1] 18.2

Unbiasedness of sample variance

var(population)
## [1] 15.95556
(1/10)*sum((population-18.2)^2)
## [1] 14.36
(1/9)*sum((population-18.2)^2)
## [1] 15.95556
all_var<-apply(all_sample, 2, var)
all_var
##   [1]  1.333333  6.333333  9.333333 13.000000 17.333333 22.333333 34.333333
##   [8] 41.333333  3.000000  5.333333  8.333333 12.000000 16.333333 27.000000
##  [15] 33.333333  4.333333  6.333333  9.000000 12.333333 21.000000 26.333333
##  [22]  7.000000  9.333333 12.333333 20.333333 25.333333 10.333333 13.000000
##  [29] 20.333333 25.000000 14.333333 21.000000 25.333333 22.333333 26.333333
##  [36] 30.333333  6.333333  9.333333 13.000000 17.333333 22.333333 34.333333
##  [43] 41.333333 10.333333 13.000000 16.333333 20.333333 30.333333 36.333333
##  [50] 14.333333 17.333333 21.000000 30.333333 36.000000 19.000000 22.333333
##  [57] 31.000000 36.333333 24.333333 32.333333 37.333333 34.333333 39.000000
##  [64] 44.333333  4.333333  6.333333  9.000000 12.333333 21.000000 26.333333
##  [71]  7.000000  9.333333 12.333333 20.333333 25.333333 10.333333 13.000000
##  [78] 20.333333 25.000000 14.333333 21.000000 25.333333 22.333333 26.333333
##  [85] 30.333333  1.000000  2.333333  4.333333 10.333333 14.333333  2.333333
##  [92]  4.000000  9.333333 13.000000  4.333333  9.000000 12.333333  9.333333
##  [99] 12.333333 14.333333  1.000000  2.333333  7.000000 10.333333  2.333333
## [106]  6.333333  9.333333  6.333333  9.000000 10.333333  1.000000  4.333333
## [113]  7.000000  4.000000  6.333333  7.000000  2.333333  4.333333  4.333333
## [120]  2.333333
# mean of all sample variance
mean(all_var)
## [1] 15.95556

lecture 9

UNBIASEDNESS ex-2

fil<-read.csv(file = "pop.csv",header = T)
fil
##     x            y z
## 1   0  -40.9567603 0
## 2   0  -31.8173316 1
## 3   0  107.1450810 0
## 4   1  -97.7407109 0
## 5   1 -117.0041975 0
## 6   1  179.2802790 0
## 7   1  -24.1607227 0
## 8   0   40.5572968 1
## 9   1  151.2887414 0
## 10  0  124.8838923 0
## 11  0   62.2545652 0
## 12  1  -63.9260760 0
## 13  0 -145.8464928 0
## 14  1   -2.7477640 0
## 15  0  -44.0767845 0
## 16  0  -13.0245172 2
## 17  1   38.2127378 0
## 18  0  167.9366431 1
## 19  1   93.6051624 1
## 20  0  147.4111576 0
## 21  1  -20.6316656 0
## 22  1  -56.5421425 0
## 23  1  209.4553604 0
## 24  0  232.3950901 1
## 25  1   83.8486289 0
## 26  1  -73.4998126 0
## 27  1  -50.1512328 0
## 28  1  -42.7356755 1
## 29  1  -49.3725404 0
## 30  1  -76.7139685 0
## 31  0   69.3881027 0
## 32  0   53.8185649 0
## 33  0  -21.4893204 0
## 34  1  -19.8374681 0
## 35  0  -49.2559555 0
## 36  0   20.8802796 0
## 37  0   54.6910402 0
## 38  0  -20.8925015 0
## 39  0  -20.2874362 0
## 40  1  -37.1932507 0
## 41  1   23.9101224 1
## 42  0  211.2839941 0
## 43  0   34.8629143 0
## 44  1  -76.6871949 3
## 45  0  112.9149960 0
## 46  1   -1.2402290 0
## 47  1   33.4339419 0
## 48  1   94.7919221 1
## 49  1  -21.9887931 1
## 50  1  -59.1032553 4
## 51  1 -219.2468873 0
## 52  0   83.1585027 0
## 53  1   76.1579654 0
## 54  0  -78.5099351 2
## 55  0   -7.0310764 0
## 56  0   87.7558202 0
## 57  1  -28.4126644 1
## 58  1 -148.9555310 2
## 59  0  107.1612030 0
## 60  0  -38.5885637 3
## 61  1  -56.3538732 0
## 62  1  158.2385502 0
## 63  1 -107.1282298 0
## 64  0  120.3250546 0
## 65  0  137.2432874 0
## 66  0    0.1859710 0
## 67  1  -10.6279767 0
## 68  0  -33.4176216 0
## 69  0  194.9965949 0
## 70  0  -56.2739201 0
## 71  1   23.2381664 0
## 72  1  144.7663063 0
## 73  1   -3.9280043 0
## 74  0   -6.9589154 0
## 75  1   62.7957178 0
## 76  0  108.1653836 0
## 77  0   87.5594111 0
## 78  0 -112.8465649 0
## 79  1   24.1107186 0
## 80  0  -22.3333949 0
## 81  0   84.7291927 0
## 82  0   43.1858067 0
## 83  1  213.4802674 0
## 84  1   36.8102713 0
## 85  0  -59.5843004 0
## 86  0   83.8387836 0
## 87  1  -14.2493291 1
## 88  0  -40.4721434 0
## 89  1  132.4941228 0
## 90  0   37.3857462 2
## 91  1  -36.3075215 0
## 92  1  -69.5186777 0
## 93  1    0.3291253 1
## 94  1  128.2298958 0
## 95  1  178.3789648 1
## 96  1  -50.9804133 0
## 97  1  -54.0817081 0
## 98  0  165.9711847 1
## 99  1    5.8837937 0
## 100 1   63.8328282 1
View(fil)

population<-fil$x+fil$y+fil$z
population
##   [1]  -40.956760  -30.817332  107.145081  -96.740711 -116.004198  180.280279
##   [7]  -23.160723   41.557297  152.288741  124.883892   62.254565  -62.926076
##  [13] -145.846493   -1.747764  -44.076785  -11.024517   39.212738  168.936643
##  [19]   95.605162  147.411158  -19.631666  -55.542142  210.455360  233.395090
##  [25]   84.848629  -72.499813  -49.151233  -40.735676  -48.372540  -75.713968
##  [31]   69.388103   53.818565  -21.489320  -18.837468  -49.255955   20.880280
##  [37]   54.691040  -20.892501  -20.287436  -36.193251   25.910122  211.283994
##  [43]   34.862914  -72.687195  112.914996   -0.240229   34.433942   96.791922
##  [49]  -19.988793  -54.103255 -218.246887   83.158503   77.157965  -76.509935
##  [55]   -7.031076   87.755820  -26.412664 -145.955531  107.161203  -35.588564
##  [61]  -55.353873  159.238550 -106.128230  120.325055  137.243287    0.185971
##  [67]   -9.627977  -33.417622  194.996595  -56.273920   24.238166  145.766306
##  [73]   -2.928004   -6.958915   63.795718  108.165384   87.559411 -112.846565
##  [79]   25.110719  -22.333395   84.729193   43.185807  214.480267   37.810271
##  [85]  -59.584300   83.838784  -12.249329  -40.472143  133.494123   39.385746
##  [91]  -35.307521  -68.518678    2.329125  129.229896  180.378965  -49.980413
##  [97]  -53.081708  166.971185    6.883794   65.832828
mean(population)
## [1] 24.89928
var(population)
## [1] 8351.911
all_sample<-combn(population,3)

all_mean<-apply(all_sample, 2, mean)
mean(all_mean)
## [1] 24.89928
all_var<-apply(all_sample, 2, var)
mean(all_var)
## [1] 8351.911
#for pc
#setwd("D:/")

#data_set<-read.csv("pop.csv")
#View(data_set)

UNBIASEDNESS ex-3

when number of sample too large for calculation .we take some number of sample from whole sample set

fil<-read.csv(file = "pop.csv",header = T)
#population<-fil$x+fil$y+fil$z
population<-exp(fil$y)-2*fil$x+3*fil$z
population
##   [1]   1.631943e-18   3.000000e+00   3.408140e+46  -2.000000e+00  -2.000000e+00
##   [6]   7.251634e+77  -2.000000e+00   4.109701e+17   5.056681e+65   1.723397e+54
##  [11]   1.088464e+27  -2.000000e+00   4.567441e-64  -1.935929e+00   7.206024e-20
##  [16]   6.000002e+00   3.940771e+16   8.589293e+72   4.489578e+40   1.046773e+64
##  [21]  -2.000000e+00  -2.000000e+00   9.232243e+90  8.470426e+100   2.600141e+36
##  [26]  -2.000000e+00  -2.000000e+00   1.000000e+00  -2.000000e+00  -2.000000e+00
##  [31]   1.364175e+30   2.361053e+23   4.648435e-10  -2.000000e+00   4.058919e-22
##  [36]   1.170012e+09   5.649591e+23   8.443099e-10   1.546245e-09  -2.000000e+00
##  [41]   2.421220e+10   5.747418e+91   1.382838e+15   7.000000e+00   1.092345e+49
##  [46]  -1.710682e+00   3.312657e+14   1.470987e+41   1.000000e+00   1.000000e+01
##  [51]  -2.000000e+00   1.304004e+36   1.188459e+33   6.000000e+00   8.839797e-04
##  [56]   1.293804e+38   1.000000e+00   4.000000e+00   3.463531e+46   9.000000e+00
##  [61]  -2.000000e+00   5.273867e+68  -2.000000e+00   1.805125e+52   4.017930e+59
##  [66]   1.204387e+00  -1.999976e+00   3.068395e-15   4.852272e+84   3.635357e-25
##  [71]   1.236538e+10   7.433751e+62  -1.980317e+00   9.501266e-04   1.869966e+27
##  [76]   9.454297e+46   1.063088e+38   9.803013e-50   2.959048e+10   1.998618e-10
##  [81]   6.272213e+36   5.693214e+18   5.167758e+92   9.693882e+15   1.326988e-26
##  [86]   2.574667e+36   1.000001e+00   2.649546e-18   3.479096e+57   1.723548e+16
##  [91]  -2.000000e+00  -2.000000e+00   2.389752e+00   4.892560e+55   2.944422e+77
##  [96]  -2.000000e+00  -2.000000e+00   1.203288e+72   3.571692e+02   5.275275e+27
mean(population)
## [1] 8.470426e+98
var(population)
## [1] 7.174812e+199
# 1st way 
some_sample<-replicate(n = 10000,expr = sample(population,size = 5,replace = F))
some_mean<-apply(some_sample, 2, mean)
mean(some_mean)
## [1] 8.978652e+98
# 2nd way
x<-replicate(10000,mean(sample(population,size = 5,replace = F)))
mean(x)
## [1] 8.605953e+98

unbiasness of mean

set.seed(13)
population<-rexp(n = 30,rate = 0.9)
# mean in unbiased estimator
mean(population)
## [1] 1.043536
all_sample<-combn(population,4)
all_mean<-apply(all_sample, 2, mean)
mean(all_mean)
## [1] 1.043536

MLE

library(MASS)
#View(birthwt)

x<-birthwt$bwt
mean(x)
## [1] 2944.587
var(x)
## [1] 531753.5
fun<-function(par){
-sum (dnorm(x,par[1],sqrt(par[2]),log=T))
}
optim(par=c(2944.587,531753.5),fun)
## $par
## [1]   2944.646 529134.694
## 
## $value
## [1] 1513.56
## 
## $counts
## function gradient 
##       53       NA 
## 
## $convergence
## [1] 0
## 
## $message
## NULL

lecture 10

x is a sample from normal distribution .Find MLE for mean & variance.

MLE Of exponaltial distribution

## 1st Way
set.seed(13)
x<- rexp(100,4)

fun<-function(t){
  sum(dexp(x = x,rate = t,log = T))
}

optimize(fun,interval = c(0,100),maximum = T)
## $maximum
## [1] 4.471106
## 
## $objective
## [1] 49.76359
## 2nd way
set.seed(13)
x<- rexp(10000,4)

fun<-function(par){
  -sum(dexp(x = x,rate = par[1],log = T))
}

optim(par = c(4),fn = fun)
## Warning in optim(par = c(4), fn = fun): one-dimensional optimization by Nelder-Mead is unreliable:
## use "Brent" or optimize() directly
## $par
## [1] 4.025781
## 
## $value
## [1] -3927.997
## 
## $counts
## function gradient 
##       20       NA 
## 
## $convergence
## [1] 0
## 
## $message
## NULL

MLE of binomial dist.(coin toss)

suppose 100 toss

## 1st way
x<-rbinom(n = 10000,size = 1,prob = 0.5)

fun<-function(t){
  sum(dbinom(x = x,size = 1,prob = t,log = T))
}

mle<-optimize(fun,interval = c(0,1),maximum = T)
mle
## $maximum
## [1] 0.4966905
## 
## $objective
## [1] -6931.254
## 2nd way
x<-rbinom(n = 10000,size = 1,prob = 0.5)
fun<-function(par){
-sum(dbinom(x = x,size = 1,prob = par[1],log = T))
}

optim(par = c(.5),fn = fun)
## Warning in optim(par = c(0.5), fn = fun): one-dimensional optimization by Nelder-Mead is unreliable:
## use "Brent" or optimize() directly
## $par
## [1] 0.5003906
## 
## $value
## [1] 6931.472
## 
## $counts
## function gradient 
##       16       NA 
## 
## $convergence
## [1] 0
## 
## $message
## NULL

MLE of Normal distribution

x<-rnorm(10000,mean=0,sd=1)
fun<-function(par){
  -sum(dnorm(x = x,mean = par[1],sd = par[2],log = T))
}

mle<-optim(par = c(0,1),fun)
mle
## $par
## [1] 0.02293321 0.99865517
## 
## $value
## [1] 14176.13
## 
## $counts
## function gradient 
##       43       NA 
## 
## $convergence
## [1] 0
## 
## $message
## NULL

lecture 11

fairness of coin

A tosses a coin 100 times and gets 70 heads. Check whether the coin is fair or not. H0: P(H)=0.5 H1: P(H)=!0.5

y<-NULL
for (i in 1:1000){
   x<-rbinom(100,1,0.5)
   y[i]<-sum(x)/100
}
y
##    [1] 0.46 0.60 0.50 0.58 0.55 0.39 0.40 0.43 0.53 0.54 0.53 0.51 0.53 0.42
##   [15] 0.50 0.47 0.52 0.53 0.44 0.51 0.52 0.49 0.46 0.56 0.46 0.45 0.51 0.56
##   [29] 0.43 0.45 0.52 0.53 0.40 0.61 0.56 0.50 0.60 0.54 0.52 0.56 0.45 0.50
##   [43] 0.55 0.46 0.50 0.49 0.47 0.52 0.60 0.54 0.50 0.56 0.50 0.43 0.55 0.45
##   [57] 0.53 0.57 0.49 0.43 0.51 0.50 0.47 0.54 0.46 0.47 0.52 0.46 0.44 0.52
##   [71] 0.50 0.55 0.42 0.45 0.40 0.47 0.48 0.49 0.46 0.43 0.47 0.47 0.53 0.51
##   [85] 0.49 0.50 0.56 0.47 0.49 0.47 0.48 0.53 0.40 0.50 0.50 0.48 0.40 0.48
##   [99] 0.53 0.47 0.57 0.49 0.53 0.50 0.54 0.56 0.47 0.54 0.45 0.55 0.54 0.37
##  [113] 0.50 0.58 0.44 0.50 0.47 0.50 0.53 0.49 0.48 0.50 0.30 0.58 0.52 0.40
##  [127] 0.52 0.40 0.51 0.52 0.43 0.57 0.40 0.50 0.54 0.57 0.49 0.48 0.48 0.46
##  [141] 0.53 0.47 0.55 0.49 0.47 0.52 0.56 0.53 0.51 0.54 0.48 0.49 0.48 0.47
##  [155] 0.52 0.50 0.49 0.49 0.58 0.62 0.46 0.46 0.56 0.46 0.59 0.54 0.54 0.49
##  [169] 0.52 0.54 0.48 0.44 0.51 0.49 0.54 0.49 0.53 0.49 0.43 0.53 0.57 0.46
##  [183] 0.53 0.42 0.49 0.45 0.60 0.46 0.60 0.47 0.54 0.49 0.51 0.49 0.39 0.54
##  [197] 0.54 0.43 0.58 0.47 0.42 0.60 0.50 0.58 0.59 0.55 0.45 0.47 0.46 0.52
##  [211] 0.57 0.48 0.52 0.50 0.60 0.52 0.53 0.50 0.50 0.48 0.47 0.53 0.50 0.48
##  [225] 0.48 0.58 0.46 0.57 0.51 0.52 0.58 0.53 0.51 0.36 0.51 0.55 0.48 0.45
##  [239] 0.49 0.44 0.48 0.42 0.61 0.45 0.49 0.53 0.46 0.52 0.49 0.52 0.52 0.57
##  [253] 0.51 0.55 0.47 0.47 0.51 0.48 0.58 0.52 0.51 0.46 0.58 0.59 0.48 0.49
##  [267] 0.45 0.55 0.45 0.49 0.34 0.40 0.58 0.48 0.40 0.45 0.39 0.56 0.49 0.51
##  [281] 0.42 0.46 0.49 0.47 0.45 0.41 0.51 0.51 0.54 0.53 0.55 0.55 0.56 0.54
##  [295] 0.42 0.48 0.56 0.55 0.50 0.52 0.57 0.43 0.54 0.47 0.46 0.48 0.44 0.50
##  [309] 0.57 0.55 0.50 0.48 0.49 0.48 0.42 0.55 0.45 0.55 0.52 0.46 0.43 0.49
##  [323] 0.49 0.39 0.49 0.47 0.48 0.56 0.51 0.56 0.48 0.47 0.55 0.43 0.59 0.47
##  [337] 0.55 0.52 0.46 0.55 0.47 0.50 0.54 0.54 0.46 0.62 0.57 0.49 0.43 0.53
##  [351] 0.52 0.41 0.46 0.45 0.53 0.54 0.61 0.54 0.55 0.49 0.53 0.49 0.44 0.46
##  [365] 0.56 0.48 0.54 0.43 0.54 0.50 0.51 0.49 0.46 0.55 0.60 0.53 0.44 0.51
##  [379] 0.52 0.50 0.48 0.52 0.41 0.58 0.50 0.44 0.52 0.42 0.48 0.50 0.49 0.53
##  [393] 0.43 0.57 0.44 0.56 0.55 0.46 0.59 0.56 0.56 0.47 0.42 0.47 0.55 0.54
##  [407] 0.54 0.48 0.48 0.53 0.55 0.47 0.45 0.47 0.52 0.48 0.49 0.61 0.50 0.55
##  [421] 0.51 0.39 0.45 0.51 0.56 0.40 0.61 0.52 0.52 0.53 0.44 0.48 0.46 0.52
##  [435] 0.51 0.48 0.56 0.55 0.44 0.54 0.49 0.48 0.46 0.50 0.51 0.46 0.51 0.53
##  [449] 0.50 0.47 0.55 0.53 0.53 0.48 0.45 0.53 0.56 0.54 0.48 0.55 0.48 0.50
##  [463] 0.52 0.44 0.53 0.39 0.55 0.56 0.52 0.51 0.56 0.43 0.54 0.50 0.53 0.53
##  [477] 0.40 0.46 0.46 0.55 0.47 0.50 0.59 0.56 0.45 0.52 0.50 0.57 0.42 0.55
##  [491] 0.40 0.42 0.44 0.50 0.53 0.53 0.52 0.54 0.51 0.50 0.41 0.49 0.57 0.60
##  [505] 0.52 0.52 0.51 0.55 0.41 0.44 0.37 0.51 0.50 0.54 0.53 0.60 0.54 0.55
##  [519] 0.44 0.57 0.47 0.49 0.55 0.47 0.57 0.56 0.54 0.45 0.52 0.53 0.48 0.59
##  [533] 0.51 0.44 0.58 0.57 0.56 0.39 0.47 0.47 0.47 0.45 0.45 0.54 0.49 0.48
##  [547] 0.45 0.50 0.54 0.45 0.49 0.63 0.56 0.39 0.58 0.43 0.53 0.50 0.53 0.59
##  [561] 0.59 0.49 0.56 0.62 0.50 0.46 0.49 0.60 0.52 0.50 0.54 0.50 0.51 0.44
##  [575] 0.51 0.48 0.41 0.44 0.41 0.49 0.44 0.39 0.52 0.42 0.54 0.50 0.50 0.44
##  [589] 0.53 0.52 0.52 0.52 0.56 0.49 0.54 0.50 0.48 0.43 0.50 0.57 0.53 0.52
##  [603] 0.56 0.47 0.50 0.47 0.61 0.44 0.57 0.55 0.52 0.43 0.48 0.55 0.50 0.48
##  [617] 0.43 0.48 0.45 0.51 0.58 0.60 0.50 0.55 0.48 0.54 0.59 0.44 0.45 0.52
##  [631] 0.46 0.47 0.45 0.46 0.49 0.51 0.59 0.49 0.53 0.49 0.41 0.49 0.54 0.53
##  [645] 0.47 0.41 0.45 0.46 0.56 0.56 0.54 0.47 0.38 0.47 0.52 0.49 0.47 0.52
##  [659] 0.42 0.51 0.44 0.54 0.45 0.57 0.61 0.48 0.50 0.50 0.49 0.49 0.51 0.52
##  [673] 0.62 0.51 0.43 0.54 0.44 0.51 0.60 0.47 0.54 0.41 0.45 0.50 0.41 0.56
##  [687] 0.47 0.48 0.51 0.55 0.52 0.43 0.46 0.44 0.57 0.44 0.53 0.53 0.49 0.54
##  [701] 0.44 0.45 0.47 0.52 0.51 0.58 0.51 0.52 0.58 0.49 0.53 0.55 0.57 0.54
##  [715] 0.51 0.52 0.51 0.51 0.48 0.58 0.53 0.56 0.43 0.54 0.59 0.56 0.56 0.46
##  [729] 0.51 0.45 0.52 0.44 0.48 0.46 0.45 0.44 0.53 0.50 0.53 0.55 0.53 0.50
##  [743] 0.51 0.51 0.55 0.48 0.52 0.45 0.57 0.46 0.41 0.47 0.53 0.46 0.49 0.56
##  [757] 0.50 0.57 0.56 0.55 0.52 0.45 0.53 0.44 0.49 0.57 0.56 0.53 0.46 0.40
##  [771] 0.50 0.47 0.48 0.52 0.46 0.52 0.55 0.51 0.51 0.52 0.50 0.48 0.45 0.48
##  [785] 0.60 0.53 0.50 0.46 0.45 0.59 0.49 0.41 0.48 0.45 0.51 0.50 0.55 0.58
##  [799] 0.41 0.51 0.51 0.55 0.50 0.44 0.45 0.59 0.44 0.55 0.52 0.48 0.49 0.53
##  [813] 0.55 0.53 0.51 0.54 0.52 0.51 0.59 0.50 0.49 0.48 0.44 0.50 0.45 0.47
##  [827] 0.52 0.42 0.56 0.47 0.47 0.50 0.47 0.49 0.54 0.52 0.50 0.45 0.42 0.47
##  [841] 0.48 0.48 0.48 0.52 0.44 0.43 0.55 0.52 0.51 0.46 0.40 0.58 0.49 0.55
##  [855] 0.37 0.48 0.47 0.51 0.45 0.47 0.41 0.53 0.45 0.40 0.56 0.51 0.51 0.58
##  [869] 0.54 0.51 0.59 0.43 0.39 0.51 0.53 0.43 0.53 0.54 0.49 0.45 0.48 0.42
##  [883] 0.48 0.44 0.46 0.56 0.49 0.50 0.52 0.41 0.49 0.49 0.48 0.43 0.56 0.49
##  [897] 0.53 0.53 0.58 0.51 0.48 0.55 0.59 0.47 0.55 0.49 0.51 0.52 0.51 0.59
##  [911] 0.55 0.53 0.55 0.48 0.58 0.55 0.45 0.47 0.45 0.53 0.45 0.51 0.58 0.55
##  [925] 0.53 0.42 0.56 0.52 0.57 0.52 0.49 0.50 0.45 0.55 0.54 0.50 0.43 0.53
##  [939] 0.42 0.55 0.48 0.50 0.45 0.43 0.47 0.55 0.49 0.54 0.50 0.46 0.53 0.54
##  [953] 0.55 0.40 0.51 0.42 0.55 0.58 0.57 0.50 0.48 0.54 0.45 0.50 0.55 0.52
##  [967] 0.49 0.52 0.51 0.49 0.52 0.44 0.54 0.52 0.51 0.53 0.60 0.52 0.51 0.53
##  [981] 0.55 0.41 0.51 0.47 0.52 0.57 0.57 0.56 0.45 0.53 0.49 0.51 0.48 0.50
##  [995] 0.50 0.45 0.52 0.58 0.51 0.64
hist(y)

(lw<-quantile(y,0.025))
## 2.5% 
##  0.4
(up<-quantile(y,0.975))
## 97.5% 
##   0.6
(pvalue<-sum(y>0.7)/length(y))
## [1] 0

lecture 12

Hypothsis ex-1

library (MASS)
#H0:bwt =3100

View(birthwt)

x<-birthwt$bwt
x_bar<-mean(x)
x_bar
## [1] 2944.587
n<-length(x)

y<-NULL
for( i in 1:1000){
  y[i]<-mean (rnorm(n=n,mean=3100,sd = sd(x)))
}
ci<-quantile(y, c(0.025,0.975))
ci
##     2.5%    97.5% 
## 2997.545 3202.605
# two tailed test
pvalue<-2*mean(y<x_bar)
pvalue
## [1] 0.004

Hypothsis ex-2(difference)

library(MASS)
#H0: MuS=MuN
#H1: MuS<MuN

x<-birthwt$bwt

x_bar<-mean(x)
(n<-length(x))
## [1] 189
s_smoke<-birthwt$bwt[birthwt$smoke==1]
s_smoke
##  [1] 2557 2594 2600 2663 2665 2769 2769 2782 2821 2906 2920 2948 2948 2977 2977
## [16] 2922 3005 3033 3042 3062 3062 3090 3132 3147 3203 3260 3303 3317 3321 3331
## [31] 3374 3430 3444 3572 3629 3637 3643 3651 3651 3756 3856 3884 3940 4238  709
## [46] 1135 1790 1818 1885 1928 1928 1936 2084 2084 2125 2126 2187 2211 2225 2296
## [61] 2296 2353 2367 2381 2381 2410 2410 2414 2424 2466 2466 2466 2495 2495
n1<-length(s_smoke)
n1
## [1] 74
s_non<-birthwt$bwt[birthwt$smoke==0]
n2<-length(s_non)
(x_mean_differ<-mean(s_smoke)-mean(s_non))
## [1] -283.7767
y_n<-NULL
for(i in 1:1000){
 
  y1<-mean(rnorm(n=n1,mean = x_bar,sd=sd(x)))
 
  y2<-mean(rnorm(n=n2,mean = x_bar,sd=sd(x)))
 
  y_n[i]<-y1-y2
}



(pvalue<-mean(y_n<x_mean_differ))
## [1] 0.005
y_n<x_mean_differ
##    [1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##   [13] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##   [25] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##   [37] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##   [49] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##   [61] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##   [73] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##   [85] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##   [97] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [109] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [121] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [133] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [145] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [157] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE FALSE
##  [169] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [181] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [193] FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [205] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [217] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [229] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [241] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [253] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [265] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [277] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [289] FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [301] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [313] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [325] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [337] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [349] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [361] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [373] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [385] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [397] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [409] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [421] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [433] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE
##  [445] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [457] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [469] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [481] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [493] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [505] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [517] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [529] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [541] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [553] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [565] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [577] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [589] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [601] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [613] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [625] FALSE FALSE FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE
##  [637] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [649] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [661] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [673] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [685] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [697] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [709] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [721] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [733] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [745] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [757] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [769] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [781] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [793] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [805] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [817] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [829] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [841] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [853] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [865] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [877] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [889] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [901] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [913] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [925] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [937] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [949] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [961] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [973] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [985] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
##  [997] FALSE FALSE FALSE FALSE

lecture 13

Hypothsis ex-1.1

library(MASS)

x<-birthwt$bwt
x_bar<-mean(x)
x_bar
## [1] 2944.587
n<-length(x)

#set.seed(013)
y<-NULL
for(i in 1: 1000){
  y[i]<-mean(rnorm(n = n,mean = 3100,sd = sd(x)))
}

mean(y<x_bar)
## [1] 0.003
mean(y>x_bar)
## [1] 0.997

lecture 14

Hypothsis ex-3(difference)

#H0 :yb = ya 
#H1 :yb != ya 

# paired two tailed test
yb<-c(201,231,221,260,228,237,326,235,240,267)
ya<-c(200,234,216,233,224,216,296,195,207,247)


d<- yb-ya
length(d)
## [1] 10
mean_d<-mean(d)
sd_d<-sd(d)


m.d<-NULL
for(i in 1:1000){
  d_s<-rnorm(10,0,sd_d)
  m.d[i]<-mean(d_s)
 
}

quantile(m.d,0.5)
##        50% 
## -0.3953587
(p<-mean(m.d>mean_d)*2)
## [1] 0

Assignment

Assignment 01

1

Generate a sample of size 400 from a Poisson distribution with lambda=5. Repeat this process for an adequate time and find the distribution of the mean.

x<-NULL

for(i in 1: 1000){
a<-rpois(n = 400,lambda = 5)
x[i]<-mean(a)
}
hist(x,freq = FALSE ,main = "Histogram of Poisson distribution with lambda=5",xlab="mean",col='7')
curve(dnorm(x,mean(x),sd(x)),add =TRUE,lwd=3,col="red")

According to histogram poisson mean follow normal distribution.

2

Prove the central limit theorem using a binomial distribution bin(10,0.3).

set.seed(34)
x<-rbinom(n = 1000,size = 10,prob = 0.3)
hist(x,main = "Population Distribution",xlab = 'mean',col="ORANGE")

binomial_mean2<-NULL
binomial_mean20<-NULL
binomial_mean70<-NULL

for(i in 1:100){
  binomial_mean2[i]<-mean(sample(x = x,size = 2,replace = FALSE))
  binomial_mean20[i]<-mean(sample(x = x,size = 20,replace = FALSE))
  binomial_mean70[i]<-mean(sample(x = x,size = 70,replace = FALSE))
}
hist(x=binomial_mean2,main = "sample Distribution (n=2)",xlab = 'mean',col="lightgreen")

hist(x=binomial_mean20,main = "sample Distribution (n=20)",xlab = 'mean',col="lightgreen")

hist(x=binomial_mean70,main = "sample Distribution (n=70)",xlab = 'mean',col="lightgreen")

The Central Limit Theorem:The sampling distribution of sample means will be approximately normal when the sample size is large(n>=30), irrespective of the distribution of the population

From histogram we show that as n increasing sample mean follows normal distribution which is the main concept of central limit theorem

3

Derive the sampling distribution of sample mean and sample standard deviation (with n and (n-1) in the denominator) when sampling from different population distributions (e.g., exponential(1.5), gamma (5,1), uniform(10,15), Poisson (8) etc.)

exponential(1.5)

set.seed(34)
x<-rexp(n = 400,1.5)
hist(x,main = "Histogram of exponential distribution  ",xlab="mean",col="blue")

a<-NULL
b<-NULL
for(i in 1: 1000){
a[i]<-mean(sample(x,50,T))
b[i]<-sd(sample(x,50,T))
}
hist(a,main = "sample distribution  ",xlab="mean",col="lightblue")

#By using n-1 denominator standard deviation =
sd(a)
## [1] 0.09456174
##By using n denominator standard deviation =
sd(a)*sqrt(49/50)
## [1] 0.09361135

gamma (5,1)

set.seed(34)
x<-rgamma(n = 400,5,1)
hist(x,main = "Histogram of gamma distribution with  g~(5,1)  ",xlab="mean",col="blue")

a<-NULL
b<-NULL

for(i in 1: 1000){
a[i]<-mean(sample(x,50,T))
b[i]<-sd(sample(x,50,T))
}
hist(a,main = "sample distribution  ",xlab="mean",col="lightblue")

#By using n-1 denominator standard deviation =
sd(a)
## [1] 0.294428
##By using n denominator standard deviation =
sd(a)*sqrt(49/50)
## [1] 0.2914688

uniform(10,15)

set.seed(34)
x<-runif(n = 400,10,15)
hist(x,main = "Histogram of uniform u~(10,15) distribution ",xlab="mean",col="blue")

a<-NULL
b<-NULL

for(i in 1: 1000){
a[i]<-mean(sample(x,50,T))
b[i]<-sd(sample(x,50,T))
}
hist(a,main = "sample distribution  ",xlab="mean",col="lightblue")

#By using n-1 denominator standard deviation =
sd(a)
## [1] 0.2169774
##By using n denominator standard deviation =
sd(a)*sqrt(49/50)
## [1] 0.2147966

Poisson (8)

set.seed(34)
x<-rpois(n = 400,lambda = 8)
hist(x,main = "Histogram of Poisson (8)  distribution ",xlab="mean",col="blue")

a<-NULL
b<-NULL

for(i in 1: 1000){
a[i]<-mean(sample(x,50,T))
b[i]<-sd(sample(x,50,T))
}
hist(a,main = "sample distribution  ",xlab="mean",col="lightblue")

#By using n-1 denominator standard deviation =
sd(a)
## [1] 0.4321971
##By using n denominator standard deviation =
sd(a)*sqrt(49/50)
## [1] 0.4278533

4

Test the fairness of a coin when the coin follows Bernoulli(0.6) distribution.

#fairness of a coin (H0: coin not fair; H1: coin fair)
set.seed(13)
y<-NULL
 for (i in 1:1000){
   s<-rbinom(1000,1,0.6)
   y[i]<-sum(s)
 }
(lw<-quantile(y,0.025))
##    2.5% 
## 568.975
(up<-quantile(y,0.975))
## 97.5% 
##   631
#P(H1)
p_H1<-sum ((568.975<y & y<631)/length(y))
p_H1
## [1] 0.949
#P(H0)
p_value<-1-p_H1
p_value
## [1] 0.051

5

Five fair coins are flipped. If the outcomes are assumed independent. Find the probability mass function of the number of heads obtained.

#probability mass function(pmf):
x<-c(0,1,2,3,4,5)
dbinom(x = x,size = 5,prob = .5)
## [1] 0.03125 0.15625 0.31250 0.31250 0.15625 0.03125
## cdf
pbinom(q = x,size = 5,prob = .5)
## [1] 0.03125 0.18750 0.50000 0.81250 0.96875 1.00000
plot(x = x,y =dbinom(x = x,size = 5,prob = .5),type="h",xlab = "No of head",ylab = "pmf")

6

It is known that screws produced by a certain company will be defected with probability 0.01 independently of each other. The company sells the screws in package of 10 and offers a money back guarantee that at most 1 of the 10 screws is defective. What proportion of packages sold must the company replace.

#defected,p=.01
#probability of at most 1 of the 10 screws is defective =p(0)+p(1) 

x<-dbinom(x = 0,size = 10,prob = .01)
x
## [1] 0.9043821
y<-dbinom(x = 1,size = 10,prob = .01)
y
## [1] 0.09135172
#proportion of packages sold must the company replace=
1-x-y
## [1] 0.0042662
##NOTE:we know that, when n is large but probability p is very small then binomial distribution is similar to poison distribution
### alternative solution
#probability of at most 1 of the 10 screws is defective =p(0)+p(1)
a<-dpois(x = 1,lambda =.1 )
a
## [1] 0.09048374
b<-dpois(x = 0,lambda =.1 )
b
## [1] 0.9048374
#proportion of packages sold must the company replace=
1-a-b
## [1] 0.00467884

7

Suppose that the probability that an item produced by certain machine will be defective is 0.1.find the probability that a sample of 10 items will contain at most 1 defective item.

#defected,p=.1
#probability of at most 1 of the 10 screws is defective =p(0)+p(1) 

x<-dbinom(x = 0,size = 10,prob = .1)
y<-dbinom(x = 1,size = 10,prob = .1)


x+y
## [1] 0.7360989

Incourse

1st incourse

Question 1

a

set.seed(99)
A<-rnorm(n = 50,mean = 3,sd = 0.4)
mean(A)
## [1] 2.899035
sd(A)
## [1] 0.4079423

b

sampdst01<-replicate(n = 1000, sd(rnorm(3,3,0.4)))
hist(sampdst01)

c

sampdst02<-replicate(10000, sd(rnorm(30,3,0.4)))

hist(sampdst02)

Question 2

a

x<-c(2,4,6,8)
px<-c(.3,.2,.4,.1)
mu<-sum(x*px)
mu
## [1] 4.6
sigma<-sqrt(sum((x^2)*px)-mu^2)
sigma
## [1] 2.009975

b

popu<-sample(x,50,replace=T, prob=px)
popu
##  [1] 6 6 2 8 6 6 2 6 2 2 6 6 6 6 6 4 6 4 4 2 6 6 4 6 2 2 2 6 8 8 6 8 4 4 4 2 2 6
## [39] 8 4 6 4 6 8 6 4 8 4 2 4

c

mean(x)
## [1] 5
all_sam<-combn(x,3)
all_sam
##      [,1] [,2] [,3] [,4]
## [1,]    2    2    2    4
## [2,]    4    4    6    6
## [3,]    6    8    8    8
#MARGIN =2 means column wise equation
#MARGIN =1 means row wise equation
sam_mean<-apply(X = all_sam,MARGIN = 2,mean)
sam_mean
## [1] 4.000000 4.666667 5.333333 6.000000
mean(sam_mean)
## [1] 5

Final