Finding an equation for the line

Question

In a country the number of students who complete high school and enroll in college that same year increased from 1.8 million in 2003 to 1.9 million in 2007 find the equation for the line including the given data points. Let x represent the number of years after 2000 and y the numbers of recent high school graduates who enrolled in college that year.

Answer 1

The data points are ( 3 , 1.8 ) AND ( 7 , 1.9 ) where x is the number of years since 2000 and y is in millions.

The slope is 0.1/4 = 0.025 or 25000

y = mx + b

1.8 = 0.025 (3) + b

1.8 = 0.075 + b

b = 1.725

The line equation is y = 0.025x + 1.725