Chapter 3 - Porbability

Libraries used:

library(knitr)
## Warning: package 'knitr' was built under R version 3.5.3
library(VennDiagram)
## Warning: package 'VennDiagram' was built under R version 3.5.3
## Loading required package: grid
## Loading required package: futile.logger
## Warning: package 'futile.logger' was built under R version 3.5.3
library(png)
library(grid)
library(gmodels)
## Warning: package 'gmodels' was built under R version 3.5.3
library(openintro)
## Please visit openintro.org for free statistics materials
## 
## Attaching package: 'openintro'
## The following objects are masked from 'package:datasets':
## 
##     cars, trees

Dice Roll

imgage <- "C:/Users/jpsim/Documents/Stat & Probability for Data/1.png"
include_graphics(imgage)

a.There is not combinations a pair of dice being rolled will result in a sum of 1.

## Combinations: ((1,4),(2,3), (3,2), (4,1))

(4/36)
## [1] 0.1111111
#Combinations (6,6)
(1/36)
## [1] 0.02777778

Poverty and Language

imgage <- "C:/Users/jpsim/Documents/Stat & Probability for Data/2.png"
include_graphics(imgage)

a.There are 4.2% of people who fall into both living below the proverty line and speaking a foreign language, therefore, the answer is no.

venn <- draw.pairwise.venn(14.6, 20.7, 4.2, c("Foreing Language", "Povery"),  scale = FALSE, fill = c("blue", "red"));
grid.draw(venn);

  1. 10.4 percent living below the poverty line and speak English at home

Poverty_foreign <- (14.6+20.7)-4.2
Poverty_foreign
## [1] 31.1
100 - Poverty_foreign
## [1] 68.9

Assortative Mating

imgage <- "C:/Users/jpsim/Documents/Stat & Probability for Data/3.png"
include_graphics(imgage)

am <- data.frame(assortive.mating)
am
##     self_male partner_female
## 1        blue           blue
## 2        blue           blue
## 3        blue           blue
## 4        blue           blue
## 5        blue           blue
## 6        blue           blue
## 7        blue           blue
## 8        blue           blue
## 9        blue           blue
## 10       blue           blue
## 11       blue           blue
## 12       blue           blue
## 13       blue           blue
## 14       blue           blue
## 15       blue           blue
## 16       blue           blue
## 17       blue           blue
## 18       blue           blue
## 19       blue           blue
## 20       blue           blue
## 21       blue           blue
## 22       blue           blue
## 23       blue           blue
## 24       blue           blue
## 25       blue           blue
## 26       blue           blue
## 27       blue           blue
## 28       blue           blue
## 29       blue           blue
## 30       blue           blue
## 31       blue           blue
## 32       blue           blue
## 33       blue           blue
## 34       blue           blue
## 35       blue           blue
## 36       blue           blue
## 37       blue           blue
## 38       blue           blue
## 39       blue           blue
## 40       blue           blue
## 41       blue           blue
## 42       blue           blue
## 43       blue           blue
## 44       blue           blue
## 45       blue           blue
## 46       blue           blue
## 47       blue           blue
## 48       blue           blue
## 49       blue           blue
## 50       blue           blue
## 51       blue           blue
## 52       blue           blue
## 53       blue           blue
## 54       blue           blue
## 55       blue           blue
## 56       blue           blue
## 57       blue           blue
## 58       blue           blue
## 59       blue           blue
## 60       blue           blue
## 61       blue           blue
## 62       blue           blue
## 63       blue           blue
## 64       blue           blue
## 65       blue           blue
## 66       blue           blue
## 67       blue           blue
## 68       blue           blue
## 69       blue           blue
## 70       blue           blue
## 71       blue           blue
## 72       blue           blue
## 73       blue           blue
## 74       blue           blue
## 75       blue           blue
## 76       blue           blue
## 77       blue           blue
## 78       blue           blue
## 79       blue          brown
## 80       blue          brown
## 81       blue          brown
## 82       blue          brown
## 83       blue          brown
## 84       blue          brown
## 85       blue          brown
## 86       blue          brown
## 87       blue          brown
## 88       blue          brown
## 89       blue          brown
## 90       blue          brown
## 91       blue          brown
## 92       blue          brown
## 93       blue          brown
## 94       blue          brown
## 95       blue          brown
## 96       blue          brown
## 97       blue          brown
## 98       blue          brown
## 99       blue          brown
## 100      blue          brown
## 101      blue          brown
## 102      blue          green
## 103      blue          green
## 104      blue          green
## 105      blue          green
## 106      blue          green
## 107      blue          green
## 108      blue          green
## 109      blue          green
## 110      blue          green
## 111      blue          green
## 112      blue          green
## 113      blue          green
## 114      blue          green
## 115     brown           blue
## 116     brown           blue
## 117     brown           blue
## 118     brown           blue
## 119     brown           blue
## 120     brown           blue
## 121     brown           blue
## 122     brown           blue
## 123     brown           blue
## 124     brown           blue
## 125     brown           blue
## 126     brown           blue
## 127     brown           blue
## 128     brown           blue
## 129     brown           blue
## 130     brown           blue
## 131     brown           blue
## 132     brown           blue
## 133     brown           blue
## 134     brown          brown
## 135     brown          brown
## 136     brown          brown
## 137     brown          brown
## 138     brown          brown
## 139     brown          brown
## 140     brown          brown
## 141     brown          brown
## 142     brown          brown
## 143     brown          brown
## 144     brown          brown
## 145     brown          brown
## 146     brown          brown
## 147     brown          brown
## 148     brown          brown
## 149     brown          brown
## 150     brown          brown
## 151     brown          brown
## 152     brown          brown
## 153     brown          brown
## 154     brown          brown
## 155     brown          brown
## 156     brown          brown
## 157     brown          green
## 158     brown          green
## 159     brown          green
## 160     brown          green
## 161     brown          green
## 162     brown          green
## 163     brown          green
## 164     brown          green
## 165     brown          green
## 166     brown          green
## 167     brown          green
## 168     brown          green
## 169     green           blue
## 170     green           blue
## 171     green           blue
## 172     green           blue
## 173     green           blue
## 174     green           blue
## 175     green           blue
## 176     green           blue
## 177     green           blue
## 178     green           blue
## 179     green           blue
## 180     green          brown
## 181     green          brown
## 182     green          brown
## 183     green          brown
## 184     green          brown
## 185     green          brown
## 186     green          brown
## 187     green          brown
## 188     green          brown
## 189     green          green
## 190     green          green
## 191     green          green
## 192     green          green
## 193     green          green
## 194     green          green
## 195     green          green
## 196     green          green
## 197     green          green
## 198     green          green
## 199     green          green
## 200     green          green
## 201     green          green
## 202     green          green
## 203     green          green
## 204     green          green
blue = subset(am, partner_female == "blue")

x = table(am$self_male, am$partner_female)
y = as.data.frame(x)
names(y)[1] = 'Self Male'
names(y)[2] = 'Partner Female'
y
##   Self Male Partner Female Freq
## 1      blue           blue   78
## 2     brown           blue   19
## 3     green           blue   11
## 4      blue          brown   23
## 5     brown          brown   23
## 6     green          brown    9
## 7      blue          green   13
## 8     brown          green   12
## 9     green          green   16
 ((sum(am$self_male =="blue")/nrow(am)) +
+  (sum(am$partner_female =="blue")/nrow(am)))- (sum(am$self_male =="blue" & am$partner_female=="blue")/nrow(am))
## [1] 0.7058824
 (sum(am$self_male =="blue" & am$partner_female=="blue")/nrow(am))/(sum(am$self_male=="blue")/nrow(am))
## [1] 0.6842105
(sum(am$self_male =="brown" & am$partner_female=="blue")/nrow(am))/(sum(am$self_male=="brown")/nrow(am))
## [1] 0.3518519
  1. The probability that a random self male from the study has a blue eyes is 56% and the probability of randomly select a partner female with blue eyes is 52.4% .Therefore, Both variables are dependent.

Books on a Bookshelf

imgage <- "C:/Users/jpsim/Documents/Stat & Probability for Data/4.png"
include_graphics(imgage)

bc <- data.frame(books)
with(warpbreaks, CrossTable(bc$type, bc$format, prop.r = TRUE, prop.c = FALSE, prop.t = FALSE, prop.chisq = FALSE))
## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## |           N / Row Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  95 
## 
##  
##              | bc$format 
##      bc$type | hardcover | paperback | Row Total | 
## -------------|-----------|-----------|-----------|
##      fiction |        13 |        59 |        72 | 
##              |     0.181 |     0.819 |     0.758 | 
## -------------|-----------|-----------|-----------|
##   nonfiction |        15 |         8 |        23 | 
##              |     0.652 |     0.348 |     0.242 | 
## -------------|-----------|-----------|-----------|
## Column Total |        28 |        67 |        95 | 
## -------------|-----------|-----------|-----------|
## 
## 
(sum(bc$format=="hardcover"))/sum(table(bc)) *
(sum(bc$format=="paperback" & bc$type == "fiction"))/(sum(table(bc))-1)
## [1] 0.1849944
(sum(bc$type=="fiction"))/sum(table(bc)) *
(sum(bc$format=="hardcover"))/(sum(table(bc))-1)
## [1] 0.2257559
(sum(bc$type=="fiction"))/sum(table(bc)) *
(sum(bc$format=="hardcover"))/(sum(table(bc)))
## [1] 0.2233795
  1. Explain why this is the case. The larger the samples the smaller the difference.

Baggage fees

imgage <- "C:/Users/jpsim/Documents/Stat & Probability for Data/5.png"
include_graphics(imgage)

num_bags <- c('no-bags', 'one-bags', 'two-bags')
bag_fee <- c(0,25,35)
pass <- c(.54, .34, .12)
sample <- data.frame(num_bags, pass, bag_fee)
average_revenue <- (sum((sample$pass*sample$bag_fee))/sum(sample$pass))
average_revenue
## [1] 12.7
sqrt(0.54*(0-average_revenue)^2 + 0.34*(25-average_revenue)^2 + 0.12*(35-average_revenue)^2)
## [1] 14.07871
avg120flight <- (65*0 + 41*25 + 14 *25 + 14 * 35)
avg120flight
## [1] 1865
x <- c(0, 1025,840)

sqrt(sum((x-mean(x))^2/(length(x)-1)))
## [1] 546.2676
sd(x)
## [1] 546.2676

Income and gender

imgage <- "C:/Users/jpsim/Documents/Stat & Probability for Data/5.png"
include_graphics(imgage)

Income_range <- c("1 to $9999 or loss",
                  "10,000 to 14,999", "15, 000 to 24,999",
                  "25,000 to 34,999", "35,000 to 49,999", 
                  "50,000 to 64,999", "65,000 to 74,999",
                  "75,000 to 99,999", "100,000 or more")
total <- c(.022, .047, 0.158, 0.183, 0.212, 0.139, 0.058, 0.084, 0.097)
x <- data.frame (Income_range, total)
x
##         Income_range total
## 1 1 to $9999 or loss 0.022
## 2   10,000 to 14,999 0.047
## 3  15, 000 to 24,999 0.158
## 4   25,000 to 34,999 0.183
## 5   35,000 to 49,999 0.212
## 6   50,000 to 64,999 0.139
## 7   65,000 to 74,999 0.058
## 8   75,000 to 99,999 0.084
## 9    100,000 or more 0.097
barplot(total)

sum(x[1:5,2])
## [1] 0.622
0.622 * 0.41
## [1] 0.25502
  1. In conculsion, the assumption that was made in part C is wrong,it appears that like events are not independent.