Question: Studies have been conducted to test the effects of drug use on mental abilities.
We tested the resilience of memory in consumer groups and frequent occasional drug (data taken from "The Residual Cognitive Effects of Heavy Marijuana Use in College Students" by Pope and Yurgelun-Todd, Journal of the American Medical Association, vol . 275, No.7).

Items sorted correctly by casual users of marijuana: n = 64, = 53.3, s = 3.6

Items sorted correctly by heavy marijuana consumers:
n = 65, = 51.3, s = 4.5
With a = 0.01, it can be said?