Question

A) Assume that a sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level. Round the margin of error to four decimal places.

95% confidence; n = 380, x = 47

B) Assume that a sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level. Round the margin of error to four decimal places.

90% confidence; n = 316, x = 183

Answer 1

A)

Given that,

Point estimate = sample proportion = = x / n = 47 / 380 = 0.124

Z_/2 = 1.96

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

= 1.96 * (((0.124 * 0.876) / 380)

Margin of error = E = 0.033

B)

Point estimate = sample proportion = = x / n = 183 / 316 = 0.627

Z_/2 = 1.645

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

= 1.645 * (((0.627 * 0.373) / 316)

Margin of error = E = 0.045