Which of the following statements are true? The relevant range of activity is approximated by a straight line. Within the relevant range of activity, total variable costs do not change. Within the relevant range of activity fixed costs remain constant in total. Outside of the relevant range, cost behavior conclusions may not be valid.

Given the following data about monthly demand, what is the approxim

forecast for May using a four month moving average?

November $=39$

December $=36$

January $=40$

February $=42$

March $=48$

April $=46$