The lower limit of a confidence interval at the 95% level of confidence for the population proportion if a sample of size 200 had 40 successes is:
A) 0.2554.
B) 0.1446.
C) 0.2465.
D) 0.1535.

Question

Quizplus · Accepted Answer

The sample proportion is 40/200 = 0.2. Using the formula for the confidence interval for a proportion, the lower limit is calculated as 0.2 - 1.96 * sqrt((0.2 * 0.8) / 200) = 0.1446.

The Lower Limit of a Confidence Interval at the 95