Michael Smith is running to become the state representative for the 12th District in Delaware. The district has 310 registered Republican voters. In an effort to plan his campaign strategy, Michael would like to estimate the average age of a Republican voter in the district. Following a random sample of 27 registered Republicans, the average age of voters was found to be 38.7 years with a sample standard deviation equal to 6.8 years.

a. Construct a 95% confidence interval to estimate the average age of registered Republicans in the 12th District.

b. What assumption needs to be made for this analysis?

c. Verify your results using PHStat.

AppendixLO1