If the formula P=0.5643y-1092.57 can be used to predict the average price of a theater ticket after 1945, for what years will the average theater ticket price ba atleast $47 dollars? Y is the actual year.

Solution:

                      0.5643y-1092.57 ≤ 47

                     0.5643y ≤ 1139.57

                                 y ≤ 1139.57/0.5643 = 2019