Question

consider the model y=4/9x + 7/3 for the relation between price and quality of chewing gum. a) what does the slope mean? b) use this equation to predict the likely rating of gum which costs 8 cent a stick
c) according to this equation what would a chewing gum with a rating of 3 be likely to cost
d) what is the largest possible domain for which the model can hold?

Answer 1

a) The slope is the coefficient of x, which in this case is 4/9. I am assuming that y is price (in cents) and x is quality. That should have been made clear.

The slope is the ratio of the change in y to the change in x.

b) Substitute y = 8 in the equation and solve for x (the quality)

c) Substitute x = 3 and solve for y

d) The lowest price is x = zero. The quality must exceed 7/3