Question

question 19 of 25
an 80% confidence interval for a proportion is found to be (0.12, 0.18). what is the sample proportion?
a. 0.16
b. 0.14
c. 0.18
d. 0.15

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

$\frac{0.12 + 0.18}{2} = \frac{0.3}{2} = 0.15$

Answer:

D. 0.15