The given regression shows the relationship between the numbers of car washed(x) and the amount earned for charity(y).
y = 10x + 20
We are to calculate the amount of charity if 50 cars are washed. Number of cars are represented by x, so by substituting x = 50 in above equation we can find the amount of charity that is earned by washing 50 cars.
y = 10(50) + 20 = $ 520
Thus, the charity can earn $520 if 50 cars come in for a wash.
