Finding average rate of change

Find the average rate of change of a function over a given interval.

Problem

Consider the function g, which is defined over all real numbers. The function table below shows the function values of g for inputs between minus, 5 and 5.
What is the average rate of change of g over the interval open bracket, minus, 1, comma, 2, close bracket?
Give an exact number.
space
Over which interval does g have a positive average rate of change?
Please choose from one of the following options.
xminus, 5minus, 4minus, 3minus, 2minus, 1012345
g, left parenthesis, x, right parenthesis0267530minus, 3minus, 5minus, 12