Discussion:
Q: The Human Resources Director of Wayjacks Inc. has administered a dexterity test to job applicants for a period of several years. She assumes that the times required to complete the task are distributed with a mean of 10.8 minutes. The Director would like to know if applicants who have completed a vocational course tend to complete the task faster than the norm. For a sample of 16 applicants with such a course, she observed the average time of 10.2 minutes and standard deviation of 1.25 minutes to complete the task.
a. Set up appropriate hypotheses, give the p-value and report your conclusions.
b. Based on the result in (a) should she reject the null hypothesis at a=0.025? Explain.
c. What assumption(s) must you make in order that your answers are valid?