Discuss the below:
Q1. A clinical trial is run to assess the effects of different forms of regular exercise on HDL levels in persons between the ages of 18 and 29. Participants in the study are randomly assigned to one of three exercise groups - Weight training, Aerobic exercise or Stretching/Yoga and instructed to follow the program for 8 weeks. Their HDL levels are measured after 8 weeks and are summarized below.
Exercise Group is Weight Training, N = 20 Mean = 49.7 Std Dev = 10.2
Exercise Group is Aerobic Exercise, N =20 Mean = 43.1 Std Dev = 11.1
Exercise Group is Stretching/Yoga, N = 20 Mean = 57.0 Std Dev = 12.5
Is there a significant difference in mean HDL levels among the exercise groups? Run the test at a 5% level of significance. HINT: SSwithin = 21,860.
Q2. Consider again the data. Suppose that in the aerobic exercise group we also measured the number of hours of aerobic exercise per week and the mean is 5.2 hours with a standard deviation of 2.1 hours. The sample correlation is -0.42.
a) Is there evidence of a significant correlation between number of hours of exercise per week and HDL cholesterol level? Run the test at a 5% level of significance.
b) Estimate the equation of the regression line that best describes the relationship between number of hours of exercise per week and HDL cholesterol level (Assume that the dependent variable is HDL level).
c) Estimate the HDL level for a person who exercises 7 hours per week.
d) Estimate the HDL level for a person who does not exercise.