A graphing calculator can do a linear regression on these points very easily. The y-intercept is 107.
_____ If you want to do this by hand, you can use the 2-point form of the equation for a line, then evaluate for x=0. .. y = (100 -102)/(35 -25)*(x -25) +102 .. y =-2/10*(0 -25) +102 .. y = 107
Here the order of operation is very important. I put few parenthesis to show you what is the correct result. First you have to multiply/divide, then u can add/subtract
