Question: To estimate the percent of district voters who oppose a certain ballot measure, a survey organization takes a random sample of 200 voters from a district. If 45% of the voters in the district oppose the measure, estimate the chance that:
a) exactly 90 voters in the sample oppose the measure:
b) more than half the voters in the sample oppose the measure.
[Assume that all voters in the district are equally likely to be in the sample, independent of each other.]