Course review. Just confused which calculation I can use in my T1-84 calculator.What other number do I need to use..40?

Workbook 7 h 20-2: Course Review Workbook 7 3. The thickness of paper is often measured using basis weight: the weight of 3000 square feet of that paper in a roll. The statistics for three truckloads of paper rolls that were expected to have basis weights of 40 pounds are shown in the table below. Mean (Ibs.) Standard Deviation Lot 1 41.20 0.59 Lot 2 42.14 0.89 Lot 3 42.61 1.19 a. Describe how the three truckloads compare. b. Assuming the basis weights are normally distributed, what is the percentage of Lot 1 rolls with basis weights above 40 pounds? Answer is 97.9%