Problem 5

The table below has data from a 2009 Canadian Journal of Human Sexuality study. The data shows gender differences in response to partner influence and social expectation questions among students who had ever had sexual intercourse. The sample for this study included only students who had ever had sexual intercourse (30.7% of the total sample) yielding 2145 respondents after corrections. The age range for the study sample was 13 to 21 years old (mean = 15.8, standard deviation = 1.19). The vast majority were 14 to 17 years old (93%) and 45% were 16 years old. Less than 2% were aged 13 or 19 to 21. If one of the students is randomly selected, find the probability that the student has had sex with one, two or three partners.
Number of partners          Male           Female          Total
               1                          428                 640          1068
               2                          163                 226          389
               3                            95                 131          226
               4+                        258                 204          462
            Total                       944                1201         2145