<PRE><B>Question 191544</B>
A consumer electronics company sells 6.7 million MP3 players per month at a price of $100 apiece; when the price is lowered to $80, the company sells 10.2 million players per month. How many MP3 players can the company expect to sell per month at a price of $75? 
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You want a function where the number of MP3 players is the dependent variable.
You have two points: (100, 6.7 million) and (80, 10.2 million)
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slope = (10.2-6.7) million/(80-100)
slope = 3.5 million/ (-20) = -0.175 million
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intercept = ??
4.7 million = (-0.175 million)*100 + b
4.7 million = -17.5 million + b
b = 22.2 million
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Equation:
f(x) = (-0.175 million)x + 22.2 million
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Then f(75) = -0.175 million * 75 + 22.2 million
f(75) = 9.075 million (# of MP3s sold if the price is $75
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Cheers,
Stan H.
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