A. The slope of the line is (46687 - 41350)/(15 - 9) = 889.5.Using the point-slope form for the equation of a line, we get
y - 41350 = 889.5(x - 9)
y - 41350 = 889.5x - 8005.5
So, y = 889.5x +33344.5
B. If x = 10, then y = 889.5(10) + 33344.5 = $42239.5
C. If y = 44908, then 44908 = 889.5x + 33344.5
889.5x = 11563.5
x = 13 years