| f"mw'\" 7.2.1: Confidence intervals for population proportions. Critical values for quick reference during this activity. J Confidence level | Critical value 10.90 2 = 1.645 1 0.95 | 2* = 1.960 1 0.99 | 2* =2.576 Jump to level 1 A poll reported 56% support for a statewide election with a margin of error of 2.38 percentage points. How many voters should be sampled for a 95% confidence interval? Round up to a whole number. Ex: 1234z | voters