Question 133386
A defense attorney charges her client $4000 plus $120 per hour.  The formula R=120n + 4000 gives her revenue in dollars for n hours of work. 
What is her revenue for 100 hours of work? 
R(100) = 120*100 + 4000
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What is her revenue for 101 hours of work.
R(101) = 120*101 + 4000
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 By how much did the one extra hour of work increase the revenue? (The increase in revenue is called the marginal revenue for the 101st hour.)
The revenue increased $120 which is the slope of the equation
which in business is call the margin..
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Cheers,
Stan H.