In a clinical trial of a cholesterol drug, 375 subjects were given a placebo, an
ID: 3055494 • Letter: I
Question
In a clinical trial of a cholesterol drug, 375 subjects were given a placebo, and 21% of them developed headaches. For such randomly selected groups of 375 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. In a clinical trial of a cholesterol drug, 375 subjects were given a placebo, and 21% of them developed headaches. For such randomly selected groups of 375 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.Explanation / Answer
Here n = 375,
p = 0.21 (21%) and
q = 1 - p = 1 - 0.21 = 0.79
The mean = n*p = 0.21 * 375 = 78.75
The Standard Deviation = Sqrt(n*p*q) = Sqrt(375 * 0.21 * 0.79) = Sqrt(62.2125) = 7.8875