R Markdown

download.file("http://www.openintro.org/stat/data/bdims.RData", destfile = "bdims.RData")
load("bdims.RData")

First Few Rows of Data

head(bdims)
##   bia.di bii.di bit.di che.de che.di elb.di wri.di kne.di ank.di sho.gi che.gi
## 1   42.9   26.0   31.5   17.7   28.0   13.1   10.4   18.8   14.1  106.2   89.5
## 2   43.7   28.5   33.5   16.9   30.8   14.0   11.8   20.6   15.1  110.5   97.0
## 3   40.1   28.2   33.3   20.9   31.7   13.9   10.9   19.7   14.1  115.1   97.5
## 4   44.3   29.9   34.0   18.4   28.2   13.9   11.2   20.9   15.0  104.5   97.0
## 5   42.5   29.9   34.0   21.5   29.4   15.2   11.6   20.7   14.9  107.5   97.5
## 6   43.3   27.0   31.5   19.6   31.3   14.0   11.5   18.8   13.9  119.8   99.9
##   wai.gi nav.gi hip.gi thi.gi bic.gi for.gi kne.gi cal.gi ank.gi wri.gi age
## 1   71.5   74.5   93.5   51.5   32.5   26.0   34.5   36.5   23.5   16.5  21
## 2   79.0   86.5   94.8   51.5   34.4   28.0   36.5   37.5   24.5   17.0  23
## 3   83.2   82.9   95.0   57.3   33.4   28.8   37.0   37.3   21.9   16.9  28
## 4   77.8   78.8   94.0   53.0   31.0   26.2   37.0   34.8   23.0   16.6  23
## 5   80.0   82.5   98.5   55.4   32.0   28.4   37.7   38.6   24.4   18.0  22
## 6   82.5   80.1   95.3   57.5   33.0   28.0   36.6   36.1   23.5   16.9  21
##    wgt   hgt sex
## 1 65.6 174.0   1
## 2 71.8 175.3   1
## 3 80.7 193.5   1
## 4 72.6 186.5   1
## 5 78.8 187.2   1
## 6 74.8 181.5   1
mdims <- subset(bdims, sex == 1)
fdims <- subset(bdims, sex == 0)

Histogram of Men’s Heights

hist(mdims$hgt)

## Histogram of Womens’s Heights

hist(fdims$hgt)

### Normal Distabution ##normal curve plotted on top

fhgtmean <- mean(fdims$hgt)
fhgtsd   <- sd(fdims$hgt)
hist(fdims$hgt, probability = TRUE)
x <- 140:190
y <- dnorm(x = x, mean = fhgtmean, sd = fhgtsd)
lines(x = x, y = y, col = "blue")

## is it normally distributaded? ## I would say it appear to follow the normal curve pretty well.

Evaluating Normal Distrabution

qqnorm(fdims$hgt)
qqline(fdims$hgt)

P Plot of Sim_norm

sim_norm <- rnorm(n = length(fdims$hgt), mean = fhgtmean, sd = fhgtsd)
qqnorm(sim_norm)
qqline(sim_norm)

more data

my r thinks it’s too much data

qqnormsim(fdims$hgt)

##Does the normal probability plot for fdims$hgt look similar to the plots created for the simulated data? That is, do plots provide evidence that the female heights are nearly normal? ## all pieces of data would concure that the female’s heights. All the plot’s look diffent, but that is because they are desined to analyze normalness in diffrent ways.

women’s weight ND]

##Histogram

fwgtmean <- mean(fdims$wgt)
fwgtsd   <- sd(fdims$wgt)
hist(fdims$wgt, probability = TRUE)
x <- 140:190
y <- dnorm(x = x, mean = fwgtmean, sd = fwgtsd)
lines(x = x, y = y, col = "blue")

## Q norm

qqnorm(fdims$hgt)
qqline(fdims$hgt)

## weight would appear to be normal as well

Normal Probablities

1 - pnorm(q = 182, mean = fhgtmean, sd = fhgtsd)
## [1] 0.004434387
sum(fdims$hgt > 182) / length(fdims$hgt)
## [1] 0.003846154

#what are the odds you will randomly select a women who weighs more then 100plbs

pnorm(q = 100, mean = fwgtmean, sd = fwgtsd)
## [1] 0.9999791

#what are the odds you will randomly select a women who’s shoter than 100cm

1 - pnorm(q = 100, mean = fhgtmean, sd = fhgtsd)
## [1] 1

on your own

##1. match # a. c # b. a # c. d # d. b ##2. why C and D slant upwards. #Most litley this indicates the graph is scewed right (or in the positive direction). ##3. Normal curve # error