Question

1. a margin of error of ±0.25 is calculated for a survey result of p = 0.40. which range represents the likely true proportion?

a. 0.15 to 0.65
b. 0.30 to 0.40
c. 0.35 to 0.50
d. 0.40 to 0.50

Explanation:

Step1: Find lower - bound

Subtract margin of error from sample proportion.
$0.40 - 0.25=0.15$

Step2: Find upper - bound

Add margin of error to sample proportion.
$0.40 + 0.25 = 0.65$

Answer:

A. 0.15 to 0.65