Question

Assume that population proportion is to be estimated from the sample described. Use the sample results to approximate the margin of error and​ 95% confidence interval.

n=560, p-0.65 Round to four decimal places as needed.

Answer 1

Solution :

Given that,

Point estimate = sample proportion = = 0.65

1 - = 1 - 0.65 = 0.35

n = 560

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z_/2 = Z _0.025 = 1.96

Margin of error = E = Z _{/ 2} * (( * (1 - )) / n)

= 1.96 * (((0.65 * 0.35) / 560)

Margin of error = E = 0.0395