In a study on the healing process of bone fractures, researchers observed the time required to completely heal a bone fracture. Ten rats were randomly divided into two groups of five. No treatment was done to one group and a medical treatment was given to the other group. The time spent (in days) to completely heal the fracture for each rat is given below:

Control: 30, 22, 28, 35, 45

Treatment: 33, 40, 24, 25, 24

a) Test to see if the mean duration of healing can be reduced by the medical treatment at = 0.01. Assume equal variances.

b) Construct a 99% confidence interval for the difference of the means of the two groups.

10. The following table shows summary data on mercury concentration in salmons (in ppm) from two different areas of the Pacific Ocean.