Question

A researcher wants to make a 99% confidence interval for a population proportion. A preliminary sample produced the sample proportion of 0.46. The sample size that would limit the margin of error to be within 0.061 of the population proportion is:

Answer 1

the sample size that would limit margin of error is 443

Explanation:

The confidence level = 99 percent = 0.99

1 - alpha = 0.99

Alpha = 1 - 0.99

= 0.01

The critical z value for alpha = 0.01 = 2.576

Sample proportion = 0.46

Margin of error E = 0.061

Sample size = p(1-p)(Z/E)²

= 0.46(1-0.46) x (2.576/0.061)²

= 0.46(0.54)(42.23)²

= 0.2484 x 1783.37

= 442.989

= 443

The sample size would be 443