The county finance department in Exercise 7.90 also wants information about renewals of disabled parking placards. Suppose that in a sample of 430 transactions for disabled parking placards, it was found that 360 were paid electronically.
a. What is the margin of error for a 95% confidence interval estimate of the population proportion of disabled renewal transactions paid electronically?
b. Without calculating, is the margin of error for a 90% confidence interval estimate of the population proportion of disabled renewal transactions paid electronically larger, smaller, or the same as that found in part a for a 95% confidence interval?

Data From Exercise 7.90

What is the most common method to renew vehicle registration? In checking a random sample of 1,250 motor vehicle renewal registrations in one county, the finance department found that 200 were mailed, 300 were paid in person at the county finance department office, and the remainder was paid online at the county’s Web site. Phone registration renewals were not available.

a. Estimate the population proportion to pay for vehicle registration renewals in person at the county finance department office. Use a 90% confidence level.

b. Estimate the population proportion of online renewals. Use a 95% confidence level.