<PRE><B>Question 980230</B>
The dollar price for a barrel of oil sold at a certain oil refinery tends to follow the demand equation below, where x is the number of barrels of oil on hand (in millions)..
p = -1/4x+160
we can write this as
p = -.25x + 160
:
a. How much should be charged for a barrel of oil if there are 3 million barrels on hand?
p = -.25(3) + 160
p = -.75 + 160
p = $159.25 a barrel
:
b. What quantity x will maximize revenue?
r(x) = x(-.25x + 160)
r)x) = -.25x^2 + 160x
Find the axis of symmetry of this equation x = -b/(2a)
x = {{{(-160)/(2*-.25)}}}
x = 320 million barrels
:
c. What price should be charges in order to maximize revenue? 
p = -.25(320) + 160
p = -80 + 160
p = $80 a barrel
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