Difference in population

Question

A city's population in the year 1960 was 287,500. In 1989 the population was 275,900 compute the scope of the population growth or decline and make a statement about the population rate of change in people.

Answer 1

(1960, 287,500)

(1989, 275,900)

slope=(287,500-275,900)/(1960-1989)

slope=11,600/-29=-400/1 or -400

the population declined by 11,600 people over 29 years

that's an average decline of 400 people per year as indicated by the slope

11,600/287,500=0.040347=4.0347 %  decline over 29 years, or 4.0347%/29=0.1391 % average yearly decline