In the study to test the effects of marijuana employ on mental capabilities, groups of light and heavy users of marijuana in college were tested for memory remembers. There were 64 light users as well as 62 heavy users. The mean number of items correctly sorted from the memory was found for each and every group. Light users correctly sorted the mean of 53.3 items, with sample SD of 3.6. Heavy users correctly sorted a mean of 51.3, with 2 samples SD of 4.5. Employ a 0.01 significance level to test the claim that population of heavy marijuana users has a lower/worse memory recall than light users.