Math 240

0: Applied Statistics home > rvals for population proportions zyB CHALLENGE ACTIVITY 7.2.1: Confidence intervals for population proportions. Critical values for quick reference during this activity. Confidence level Critical value 0.90 2* = 1.645 0.95 z* = 1.960 0.99 z* = 2.576 Jump to level 1 A poll for a statewide election has a margin of error of 1.63 percentage points. How many voters should be sampled for a 99% confidence interval? Round up to the nearest whole number. EX: 1234 $ voters