Question

question 21 of 40
an 80% confidence interval for a proportion is found to be (0.27, 0.33). what is the sample proportion?
a. 0.33
b. 0.29
c. 0.31
d. 0.30

Explanation:

Step1: Find midpoint of interval

The sample proportion is the midpoint of the confidence interval. Calculate as $\frac{lower + upper}{2}$.

Step2: Substitute values

$\frac{0.27 + 0.33}{2} = \frac{0.60}{2} = 0.30$

Answer:

D. 0.30