Question

A sociologist is researching individual's out-of-pocket monthly expenses towards prescription drugs. With the knowledge that s = 9.285, determine the sample size required to estimate the mean out-of-pocket individual monthly prescription drug expenses within $1.50 with 95% confidence. Choose the best answer. Group of answer choices 148 147 104 127

Answer 1

Solution :

Given that,

standard deviation = = 9.285

margin of error = E = $1.50

At 95% confidence level the z is ,

   = 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05/ 2 = 0.025

Z/2 = Z0.025 = 1.96

Sample size = n = ((Z/2 * ) / E)2

= ((1.96 *9.285 ) / 1.50)2

= 147

Sample size = 147 ,   Option 2nd is correct.