Expert: Sherman D. - 7/11/2007

Question
QUESTION: Can you walk me through the steps of solving this equation and others like it.  Your help is greatly appreciated.

Suppose that a certain commodity's demand equation has the form p = mx + b, where x is the quantity demanded and p is the unit price in dollars. Suppose that the quantity demanded is 1226 units when the unit price is $156 and 1541 units when the unit price is $63. For the demand equation, p = mx + b, find m. (Round answer to 3 decimal places.)

ANSWER: (1226,156) and (1541,63)

m = (63 - 156)/(1541 - 1226)
m = (-93)/315
m = -.295

(x1,y1) and (x2,y2)
m = (y2 - y1)/(x2 - x1)

thats the slope formula

---------- FOLLOW-UP ----------

QUESTION: I have another one that seems similar...but since I suck at math, I need your help again!  Thanks!

Producers will make 1528 computers available when the unit price is $27. At a unit price of $50, 5907 computers will be marketed. If the supply equation is linear, how many computers would be marketed at a unit price of $41? (Round answer to whole number.)

Answer
(1528,27) and (5907,50)

m = (50 - 27)/(5907 - 1528)
m = (23/4379)

(1528,27), m = (23/4379)

27 = (23/4379)(1528) + b
27 = (35144/4379) + b
b = 27 - (35144/4379)

41 = (23/4379)x + (27 - (35144/4379))
41 - 27 + (35144/4379) = (23/4379)x
x = (14 + (35144/4379))/(23/4379)
x = about 4193 computers

ANS : 4193 computers