We Want to Estimate with 99 Percent Confidence the Percentage

Multiple Choice

We want to estimate with 99 percent confidence the percentage of buyers of cars who are under 30 years of age.A margin of error of 5 percentage points is desired.What sample size is needed? In an earlier sample we found a 99 percent confidence interval of buyers under 30 years of age to be [.18 .27].

A) 104
B) 664
C) 392
D) 523