7. Suppose a random sample of 25 people at a local weight-loss center is taken and the mean weight loss is found to be 12 lb. From past history, the standard deviation is known to be 3 lb. Test the hypothesis

that the mean weight loss for all the members of the weight-loss center is 10 lb against the alternative that it is more than 10 lb. The level of significance is 0.05.

8. Redo question 7, but assume that the standard deviation is not known and that 3 lb represents the sample standard deviation. The level of significance is 5%.