A University Wants to Estimate the Average Distance That Commuter

Multiple Choice

A university wants to estimate the average distance that commuter students travel to get to class with an error of ± 3 miles and 90 percent confidence. What sample size would be needed, assuming that travel distances are normally distributed with a range of X = 0 to X = 50 miles, using the Empirical Rule μ ± 3σ to estimate σ.

A) About 28 students
B) About 47 students
C) About 30 students
D) About 21 students