15. The average cost of a loaf of bread in 1950 was approximately 12 cents, and by 1990 the cost was about 70 cents. Which linear equation models the increase of the price of a loaf of bread? (Let x represent the number of years since
1900.)
O
y = 1.45x + 10.55
O
y = 1.45x - 84.5
y = 0.69x - 22.5
none of these