How to find the slope intercept form when the slope is undefined?

What is the average rate of change for this function for the interval from x=2 to x=4 ?

The circumference of a redwood tree trunk is 20π ft, and it is 100 ft tall. what is the approximate volume of the redwood tree trunk? 1,000π ft3 10,000π ft3 4,000π ft3 40,000π ft3

E. which of the following is not a possible probability? a. 25/100 b. 1.25 c. 1 d. 0