Chapter 11 Data Analysis and Statistics - 11.4 Select and Draw Conclusions from Samples - 11.4 Exercises - Problem Solving - Page 771: 32

2500

To be confident, the margin of error for each should be 2 percent or less. We use the margin of error equation to find: $$margin\ of \ error =\times \frac{1}{\sqrt{n}}\\ n=(margin\ of \ error)^{-2} \\ n=(.02)^{-2} \\ n=2500$$