The marketing department at Cable TV (CTV) wants to know how promotional advertising affects the number of viewers for the Saturday Night Movie. Research shows that 10 million viewers watched the movie when CTV ran 15 one-minute ads on Friday. When they ran 25 one-minute ads on Friday, the movie had 17 million viewers. Use linear interpolation to estimate the number of viewers if CTV runs 20 one-minute ads on Friday.

Ok... wait here while I do all the work and figure this out for you.