Question

Suppose you want to estimate the proportion of traditional college students on your campus who own their own car. From research on other college​ campuses, you believe the proportion will be near 30​%.What sample size is needed if you wish to be 98​% confident that your estimate is within 0.02 of the true​ proportion?

Suppose you want to estimate the proportion of traditional college students on your campus who own their own car. From research on other college campuses, you believe the proportion will be near 30%. What sample size is needed if you wish to be 98% confident that your estimate is within 0.02 of the true proportion? A sample sie is needed.

Answer 1

Z for 98% confidence interval = Z_0.01 = 2.33

Margin of error = Z_0.01 * sqrt(p * (1 - p) / n)

or, 0.02 = 2.33 * sqrt(0.3 * (1 - 0.3) / n)

or, n = 2850.17

or, n = 2851