A cereаl cоmpаny clаims that there are at least 80 raisins in every bоx оf its raisin bran cereal. To test this claim, a consumer advocacy group randomly selects 10 boxes of raisin bran and counts the number of raisins in each box. The sample has a mean of 77.8 raisins and a standard deviation of 5.5 raisins. Using a significance level of 0.05, test the company's claim. The conclusion is :