Use the table, which shows the number of pounds of skim milk, y , consumed per person in the United States in year x. Let x represent the number of years since
1980.

a. Use the model y = 2x + 23 to estimate the number of pounds
consumed in 1994. Is this linear interpolation or linear
extrapolation?

b. Use the model y = 2x + 23 to estimate the number of pounds consumed in
1999. Is this linear interpolation or linear extrapolation?
x y
1980 26.9
1985 27.4
1990 42.8
1992 46.2
1995 53.9
1996 55.7