Challenge activities 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 2* = 1.960 0.99 2* = 2.576 377222.2338710.qx3zay7 Jump to level 1 In a poll of 1000 randomly selected voters in a local election, 21 voters were against school bond measures. What is the sample proportion p? Ex: 0.1232 What is the margin of error m for the 95% confidence level? Ex: 0. 123 2 1 2 4 Check Next Feedback CHALLENGE