CHALLENGE ACTIVITY 5.8.1: 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 V In a poll of 1000 randomly selected voters in a local election, 7 voters were against school bond measures. What is the 99% confidence interval? Ex: 0. 123 : Ex. 0.123 ] [smaller value, larger value]