What is  the average rate of change of the function f(x)=2(3)^x from x = 2  to x = 4?   enter your answer in the box.

72

The key is "average rate of change". So just calculate the function for x=2 and x=4. Subtract the 2 calculated values to get the delta change, and then divide by the delta change in x. (4-2) = 2. So
f(2) = 2*3^2 = 2 * 9 = 18
f(4) = 2*3^4 = 2 * 81 = 162

And 162 - 18 = 144.

Finally, 144/2 = 72.

So the average rate of change from x=2 to x=4 is 72.

Aand b is what i think

Ithink it would be 1.24 pounds