Problem 4

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 partner or four or more 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