the line of best fit would be something like in the picture(but straighter)
you would get the equation of it by using y = mx+c
m = the change of y divided by the change of x on the line
c = when the line was on the y axis
put the values in y = mx + c and you have the equation
once you have that just replace x with 100 and rearrange it to equal y and you have the customers
