SOLUTION: In 1990, a music store sold 250 CDs per day, in 1995, they sold 175 CDs per day. Assuming a linear relationship, how many CDs did the store sell per day in 2005?

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Question 875427: In 1990, a music store sold 250 CDs per day, in 1995, they sold 175 CDs per day. Assuming a linear relationship, how many CDs did the store sell per day in 2005?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Three points are (1990, 250), (1995, 175), (2005, y).

The first two points define the linear relationship:
m=%28175-250%29%2F%281995-1990%29
m=-75%2F5
m=-15
-
y=mx%2Bb
b=y-mx
b=175-%28-15%2A1995%29
b=30100
highlight_green%28y=-15x%2B30100%29
-

Find y for x=2005:
highlight%28y=-15%2A2005%2B30100%29