In 1980 median family income was about $18,000 and in 2000 it was 40,000.

(a) Find slope of line passing through points (1980, 18,000) and (2000, 40,000)
(b) Interperate slope as a rate of change
(c) If the trend continues, estimate the median family income in 2006.

slope=changeinincome/timeinyears

a. graph the slope
c. extend the graph to 2006