For the binomial distribution described by the conditions in Exercise, find the standard deviation by evaluating 1npq. Some books use the expression 1np(1 p) for the standard deviation. Will that expression always yield the same result?
In exercise In a clinical trial of the cholesterol drug Lipitor, 270 subjects were given a placebo, and 7% of them developed headaches. For such randomly selected groups of 270 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.