install.packages(“rmarkdown”)

# sets wd to the path on my computer; 
setwd("C:\\Users\\hmon1\\Desktop\\10A Homework\\") #this is where you downloaded the HW1.csv file

# loads in data for the full population
pop<-read.csv("HW1.csv")

# sets the seed for the random number generator
set.seed(48183130)  #use your student ID instead of 12345678

# assigns a "random" sample of 200 from the population to 'data'
data<-pop[sample(1:nrow(pop), 200, replace=FALSE),]

# produces a cross tabulation table.
crosstab <-table(data$Sex,data$Smokes)
crosstab

##         
##          No Yes
##   Female 44  38
##   Male   41  77

# get and round cell and marginal means;
round(prop.table(crosstab),2) #creates cell probabilities

##         
##            No  Yes
##   Female 0.22 0.19
##   Male   0.20 0.38

round(prop.table(crosstab,1),2) #creates row probabilities

##         
##            No  Yes
##   Female 0.54 0.46
##   Male   0.35 0.65

round(prop.table(crosstab,2),2) #creates column probabilities

##         
##            No  Yes
##   Female 0.52 0.33
##   Male   0.48 0.67