You wish to construct a 90% confidence interval to compare two proportions.If we wish to obtain a margin of error of at most 0.03,what sample size should we take from each group? Assume equal sample sizes.
A)752
B)1504
C)1503
D)751
E)1984

Question

Quizplus · Accepted Answer

To calculate the sample size for a given margin of error in a confidence interval for two proportions, we use the formula: n = (Z^2 * (p1(1-p1) + p2(1-p2))) / E^2. For a 90% confidence interval, Z is approximately 1.645. Assuming p1 and p2 are both 0.5 (worst-case scenario for maximum variability), and E is 0.03, the calculation gives a sample size of approximately 1504 for each group.

You Wish to Construct a 90% Confidence Interval to Compare