Twenty People Participate in a Weight-Loss Program for 2 Months

Multiple Choice

Twenty people participate in a weight-loss program for 2 months.Their weights after the 2 months are compared to their starting weights.What kind of mean difference might be expected if the null hypothesis is true for a paired-samples t test?

A) a loss of pounds, on average, showing the effectiveness of the program
B) a negative mean difference, indicating significant weight loss
C) no change in weight or weight gain, indicating that the program does not work
D) weight loss, indicating that the program does not work