A study is conducted to test the area of nerve fibers in NORMAL and DIABETIC rats, A sample from the DISTAL and PROXIMAL ends of each nerve fiber is measured for each rat. Therefore, we have GROUP...

A study is conducted to test the area of nerve fibers in NORMAL and DIABETIC rats, A sample from the DISTAL and PROXIMAL ends of each nerve fiber is measured for each rat. Therefore, we have GROUP (NORMAL versus CONTROL) and LOCATION (DISTAL versus PROXIMAL) as independent variables, with location as a repeated measure (each rat nerve is measured at each end of the nerve fiber).The data are shown here:

Write a SAS program to enter these data and run a two-way analysis of variance, treating the location as a repeated measure. Use the REPEATED option for the LOCATION variable. Is there any difficulty in interpreting the main effects'? Why?