CHALLENGE ACTIVITY 3.3.1: Confidence intervals for population proportions. Critical values for quick reference during this activity. Confidence level | Critical value 0.90 2* = 1.645 0.95 2* = 1.960 0.99 2* = 2.576 428316.2590774.qx3zqy7 Start In a poll of 1000 randomly selected voters in a local election, 423 voters were against fire department bond measures. What is the sample proportion p? Ex: 0.123 What is the margin of error m for the 95% confidence level? Ex: 0.123 1 2 3 4 Check Next