According to the 2017 Survey of Physician Appointment Wait Time, patients had to wait an average of 24 days to schedule a new appointment with a doctor. A random sample of 40 patients in 2018 was selected and the number of days they had to wait to schedule an appointment was recorded. These data can be found in the Excel file titled average_wait_times.xlsx.

a. Perform a hypothesis test using α = 0.05 to determine if the average number of days appointments are booked in advance has changed since 2017.

b. Determine the precise p-value for this test using Excel.