SOLUTION: The figure below shows how the price of Amazon's Kindle has decreased over time. The green line is a trend line. (You can check that the hash marks on the horizontal axis are one-m

Algebra ->  Equations -> SOLUTION: The figure below shows how the price of Amazon's Kindle has decreased over time. The green line is a trend line. (You can check that the hash marks on the horizontal axis are one-m      Log On


   



Question 999588: The figure below shows how the price of Amazon's Kindle has decreased over time. The green line is a trend line. (You can check that the hash marks on the horizontal axis are one-month intervals.)
http://www.webassign.net/craudql2/3-1-022.png



The trend line estimates that the price was $432 in November 2007 and $80 in September 2011. (That is an interval of 46 months.) Use the slope of the trend line to determine by how much the price of a Kindle should decrease every six months. (Round your answer to two decimal places.)

Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
Well, you don't need the picture because the decrease in y (the price) is
$432 - $80 = $352
in 46 months (the change in x)...
so the slope is
-$352/46 months = -$7.65/month
so for six months, the change in price is six times that or
6(-7.65)=-$45.90