Help. ​

1990 nearly lies in the middle of the years 1972 and 1997. Since it is given that the amount of milk produced can be modeled using a linear model, I would expect the approximate amount of billions of pounds of milk would be the average of the amount produced for those given years.

Let m = milk produced (in billions of pounds)

$m\approx\frac{7+8}{2}=\frac{15}{2}=7.5$

Therefore, the third answer choice is correct.