Question

In Lab#2, suppose you found that the mass of 15 shots to be 21

Answer 1

15 / 21 = 75 / x.....15 shots to 21 grams = 75 shots to x grams
cross multiply
(15)(x) = (75)(21)
15x = 1575
x = 1575 / 15
x = 105 grams <===

Answer 2

Take 75 *21 to get 1,575 mass then divide it by 15 shots and you will get 105.the mass to be expected is 105