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 377112.2338738.qx32cy7 Start In a poll of 1000 randomly selected voters in a local election, 884 voters were against school 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 Check Next