SOLUTION: In 2008, a school's enrollment was 400 students. In 2012, the school's enrollment was 640 students. Which linear model represents the school's enrollment, s, as a function of t, th

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Question 1185412: In 2008, a school's enrollment was 400 students. In 2012, the school's enrollment was 640 students. Which linear model represents the school's enrollment, s, as a function of t, the number of years after 2005?
Found 2 solutions by ikleyn, greenestamps:
Answer by ikleyn(52802) About Me  (Show Source):
You can put this solution on YOUR website!
.

As the problem is posed, the year 2005 is irrelevant to the problem.


May be, the school did not exist in 2005, 2006 and 2007.



Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


Sometimes you just have to put put up with the answers that tutor @ikleyn sometimes gives....

Of course the statement of the problem implies that the school existed in 2005.

And even if it didn't, the statement of the problem would still be valid...!

The change in enrollment in the 4 years from 2008 to 2012 was +240, so the slope of the graph of student enrollment is 240/4 = 60. So the linear equation is of the form

y=60t+b

Since the equation is to be with t being the number of years after 2005, use the data point (x,y)=(2008-2005,400)=(3,400) to determine b.

400=60%283%29%2Bb
400=180%2Bb
b=220

ANSWER: y=60t%2B220