A polling agency is investigating the voter support for a ballot measure in an upcoming city election.
Question:
A polling agency is investigating the voter support for a ballot measure in an upcoming city election. The agency will select a random sample of 500 voters from one region, Region A, of the city. Assume that the population proportion of voters who would support the ballot measure in Region A is 0.47.
(a) What is the probability that the proportion of voters in the sample of Region A who support the ballot measure is greater than 0.50 ?
The polling agency will take another sample from a different region, Region B, of the city. The agency plans to select a random sample of 400 voters. Assume that the population proportion of voters who would support the ballot measure in Region B is 0.51.
(b) Describe the sampling distribution of the difference in sample proportions (Region B minus Region A).
(c) What is the probability that the two sample proportions will differ by more than 0.05 ?
Applied Statistics and Probability for Engineers
ISBN: 978-1118539712
6th edition
Authors: Douglas C. Montgomery, George C. Runger