The graph shows the function f(x). Which value is closest to the average rate of change from x = 1 to x = 3?

−3.5 - I know that this is the answer
​​ −2.3 -
​​−2.3
​​ −1.8
​​ −0.3 -

i know that the answer is -3.5 but i need someone to explain the steps please

Paul bakes raisin bars in a pan shaped like a rectangular prism. the volume of the pan is 252 cubic inches. the length of the pan is 12 inches, and its width is 10 1/2 inches. what is the height of the pan? enter your answer in the box. will give brialist and pointsss !