I am doing an ANOVA analysis, and to correct for normality, I used a log transformation on the response variable, RATING. I am trying to display some summary statistics. When I find the means of RATING and LOG_RATING, LOG_RATING is close to what I calculate the value to be, but not exactly the same. As in log(RATING) does not equal LOG_RATING. There is no missing data, so I am very confused.
Cohort is a categorical value 1 through 6. Rating is quantitative.
Here is the relevant code, output, and what log(RATING) should equal. Thoughts?
DATA SHEET1; SET SHEET1; LOG_RATING=LOG(RATING); RUN; PROC SORT DATA=SHEET1; BY COHORT; RUN; PROC MEANS DATA=SHEET1 N MEAN VAR MAXDEC=2 ; CLASS COHORT; BY RATING; RUN;