Question

In a clinical trial of a cholesterol? drug, 316 subjects were given a? placebo, and 23%

of them developed headaches. For such randomly selected groups of 316 subjects given a? placebo, identify the values of? n, p, and q that would be used for finding the mean and standard deviation for the number of subjects who develop headaches.

Answer 1

n = 316

p = 0.23

q = 1 - p = 1 - 0.23 = 0.77

mean = n * p = 316 * 0.23 = 72.68

standard deviation = sqrt(np(1 - p))

                               = sqrt(316 * 0.23 * (1 - 0.23))

                               = 7.481