A random sample of 500 adult residents of Maricopa County indicated that 385 were in favor of increasing the highway speed limit to 75 mph, and another sample of 400 adult residents of Pima County indicated that 267 were in favor of the increased speed limit. a) do these data indicate that there is a difference in thesupport for increasing the speed limit between residents of the twocounties? Use α = 0.05. What is the P-value forthis test?
b) construct a 95% confidence interval on the difference inthe two proportions. Provide a practical interpretation ofthis interval.