Can anyone help with this please?

2. Consumer Reports conducted tests on the safety of cereal grains. They found arsenic in rice mean and rice-based foods, including infant rice cereals. n (ppb) stdev Rice readily absorbs arsenic from the Rice 20 73.5 20.21 environment, about 10 times more of it than other Brown Rice 22 95.7 38.15 grains. For their study, Consumers considered the most popular brands of baby cereals, and randomly selected specimens from each. They considered Brown Rice separate from White Rice. Results are shown in the table. At the 5% significance level, is there a difference in arsenic levels in the 2 types of rice? (Assume normal distrubution.)