How do you find the average of 10.4, 10.2,10

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.

The ratio of the height of two similar cylinders is 4 to 3 what is the ratio of their volumes

Can someone me with these questions? ?