While investigating a point source epidemic

  1. While investigating a point source epidemic it was found that 120 students ate five different
    foods (meat burgers, fried fish, steak, and rice and fruit salad. The relative risk was calculated for
    all those five foods. It was concluded that fish was not responsible for this epidemic. The relative
    risk of fish is:

a) 0.7
b) 1.2
c) 1.7
d) 3.0
e) 7.0
Key: True: a

2.In a prospective study of the relationship between oral contraceptive use and the subsequent
risk of developing endometrial cancer, a cohort of 1000 women were followed for 5 years. The
results were as follows:

Present Absent
A 245
B 75
C 50
D 630

A + C = 295 B + D = 705 n = 1000