Workday- Section 10.2
-Has there been grade inflation at Northgate? Ten years ago the average GPA was 2.35 with a standard deviation of 0.4. A sample of 100 randomly chosen students had a GPA of 2.45 last fall. Is this normal random variation, or is there good evidence at the alpha=.05 level that grades have risen?
The Practice of Statistics, First Edition.
Yates, Moore, McCabe