Birth Rate In 1990 the number of births per 1000 people in the United States was 16.7 and decreasing, on average, at 0.136 birth per 1000 people each year. (Source: National Center for Health Statistics.)

(a) Write a formula for a linear function that mod-els the birth rate x years after 1990.

(b) Estimate the birth rate in 2012 and compare this estimate to the actual value of 13.7