At Western University, the historical mean of scholarship examination scores for freshmen applications is 900. A historical population standard deviation is 180. Each year, the assistant dean uses a sample of applications to determine whether the mean examination score for the new freshman applications has changed.
a. State the hypothesis (H0 and HA).
b. What is the 95% CI estimate of the population mean examination score if a sample of 200 applications provided a sample mean of 935?
c. Use the CI to conduct a hypothesis test using α = .05. What is your conclusion?