Question

Use the given data to find the minimum sample size required to estimate a population proportion or percentage. Margin of​ error seven percentage​ points; confidence level 90​%; from a prior​ study, is estimated by the decimal equivalent of 54​%

n=_____ (round to the nearest integer.)

Answer 1

137

Explanation:

Given the following :

Margin of Error (E) = 7% = 0.07

Confidence level = 90% = 0.9

Prior study (p) = 54% = 0.54

Using the sample size formula:

([Z/E]^2) × p × (1 - p)

(1 - p) = 1 - 0.54 = 0.46

Z score at 90% confidence interval. = 1.645

[(1.645 / 0.07)^2] * 0.54 * 0.46

(23.5^2) * 0.54 * 0.46

552.25 * 0.54 * 0.46

= 137.1789

= 137

Sample size = 137