According to the Journal of the American Medical Association, a resident doctor worked an average of 59.3 hours per week during 2006–2008. In 2010, the Accreditation Council for Graduate Medical Education, which certifies residency programs in hospitals, developed a plan to reduce the long hours as well as to reduce the standard deviation of hours the doctors work to less than 8 hours per week. To investigate the plan’s effectiveness, a random sample of the hours 20 residents worked per week was selected in 2014. The data are shown in the following table, and can be found in the Excel file resident hours.xlsx.

53 57 52 65 70 51 55 61 49 61 54 64 44 57 55 60 53 61 51 56

a. Using a = 0.05, determine if the standard deviation of working hours per week is below 8 hours in 2014.

b. Verify your results using PHStat.

c. Interpret the p-value obtained from the software.

AppendixLO1