In a clinical trial of a cholesterol drug, 451 subjects were given a placebo, and 21 % of them developed headaches. For such randomly selected groups of 451 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.

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Mathematics

Kathryn Wall

Yesterday, 23:28

In a clinical trial of a cholesterol drug, 451 subjects were given a placebo, and 21 % of them developed headaches. For such randomly selected groups of 451 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.

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Marley Briggs · Answer 1

n=451

p=0.21

q=0.79

Step-by-step explanation:

The value of n is the population size, in this case 451 total subjects that were given placebo. p refers to a sample population with certain attribute, which is the proportion of subjects who develop headaches. In this case the value of p = 21%=0.21. q is the proportion of the population that do not have the attribute in question (headaches). q=1-p, therefore q = 1-0.21=0.79.

To find the standard deviation the formula is: σ = √npq

Substituting the values: σ = √ (451) (0.21) (0.79) = 8.65.