# eval=FALSE
## install.packages("PairedData")


# message=FALSE

#Part 1
lipids <- read.delim("http://myweb.uiowa.edu/pbreheny/data/lipids.txt")

#Part 2 & 3
library(PairedData)
data("Anorexia")
data("Corn")

#Part 4
lister <- read.delim("http://myweb.uiowa.edu/pbreheny/data/lister.txt")



# 
t.test(lipids$TRG, mu = 120)


# 
# create a new column
Anorexia$diff <- Anorexia$Post-Anorexia$Prior


# 
SE <- sd(Anorexia$diff)/sqrt(17)


# 
t <- (mean(Anorexia$diff) - 0) / SE

2*(1-pt(t, df=16))


# 
## Test for Post - Prior
t.test(Anorexia$Post, Anorexia$Prior, paired = TRUE)


# 
# n is not specified 
power.t.test(delta = mean(Anorexia$Post-Anorexia$Prior), power = .99, 
             sd = sd(Anorexia$Post-Anorexia$Prior), type = "paired")


# 
power.t.test(delta = mean(Anorexia$Post-Anorexia$Prior), n = 50, 
             sd = sd(Anorexia$Post-Anorexia$Prior), type = "paired")


# 
tab <- table(lister)
tab


# 
chisq.test(tab, correct = FALSE)

fisher.test(tab)


# 
chidata <- data.frame("Method" = c(rep("Laptop", 67), rep("Hand", 76)), 
                      "Result" = c(rep("Passed", 44), rep("Failed", 23), rep("Passed", 56), rep("Failed", 20)))

tab <- table(chidata)