If the estimated population proportion is .30 based on previous studies, and the acceptable error is plus or minus 5 percent, and the z-value for a 95 percent level of confidence is 1.96, the needed sample size is approximately:
A)323
B)187
C)36
D)212
E)554

Question

Quizplus · Accepted Answer

The sample size (n) can be calculated using the formula: n = (Z^2 * p * (1-p)) / E^2, where Z is the z-value, p is the estimated population proportion, and E is the acceptable error. Plugging in the values: n = (1.96^2 * 0.30 * 0.70) / 0.05^2 ≈ 323.

If the Estimated Population Proportion Is