Appendix
#importing data file
setwd("D:/School/UWI/Level 2/Sem 2/STAT2001/R Lab")
mel<-read.csv("./melanoma.csv")
attach(mel)
#to perform two-sample test of proportions
#using ulcer and sex variables, aplha=0.05
#Ho: mu_1 = mu_2
#Ha: mu_1 =/= mu_2
prop.test(table(ulcer, sex), correct=FALSE)
#from results, p=0.01617 < alpha=0.05 => reject null
#at 5% significance level, there is enough evidence to prove that the occurrence
#of ulcers in men and women with melanoma are not the same.
#the 95% Confidence Interval was found to be (0.03119, 0.29827)