the birth rate in a certain country in 1992 was 14.9 births per thousand population. in 2002, the birth rate was 14.14 births per thousand.. a. let x represent years after 1992 and y represent the birth rate. assume that the relationship between x and y is linear over this period. write a linear equation that relates y in terms of x. b. use the linear equation from part (a) to estimate the birth rate in this country in the year 2012.