SOLUTION: A local theme part found that if the price of admission was $11, the attendance was about 100 customers per day. When the price of admission was dropped to $6, attendance increase

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Question 1018257: A local theme part found that if the price of admission was $11, the attendance was about 100 customers per day. When the price of admission was dropped to $6, attendance increase to about 1700 per day. Write a linear equation for the attendance in terms of the price. (A=mp+b)
Found 2 solutions by josgarithmetic, josmiceli:
Answer by josgarithmetic(39623) About Me  (Show Source):
You can put this solution on YOUR website!
Ordered pair are as (p,A) for price p and attendance, A.

Two points described are (11,100) and (6,1700). You want to find the slope-intercept equation for the line containing these two points.

A=mp%2Bb
b=A-mp
-
m=%281700-100%29%2F%286-11%29=1600%2F%28-5%29=-320
-
Pick either point...
b=100-%28-320%29%2A11
b=100%2B320%2A11
b=3620
-
highlight%28A=-320p%2B3620%29

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +A+ = attendance /day
Let +p+ = price of admission
----------------------------
When price of admission stays at $11:
+A+=+m%2Ap+%2B+b+
(1) +100+=+m%2A11+%2B+b+
When price drops to $6:
(2) +1700+=+m%2A6+%2B+b+
---------------------
Subtract (1) from (2)
(2) +1700+=+m%2A6+%2B+b+
(1) +-100+=+-m%2A11+-+b+
----------------------
+1600+=+-5m+
+m+=+-320+
and
(1) +100+=+m%2A11+%2B+b+
(1) +100+=+%28-320%29%2A11+%2B+b+
(1) +100+=+-3520+%2B+b+
(1) +b+=+3620+
-------------------------
The equation is:
+A+=+-320p+%2B+3620+
----------------------
check:
( 11, 100 )
+A+=+-320p+%2B+3620+
+100+=+-320%2A11+%2B+3620+
+100+=+-3520+%2B+3620+
+100+=+100+
and
( 6, 1700 )
+A+=+-320p+%2B+3620+
+1700+=+-320%2A6+%2B+3620+
+1700+=+-1920+%2B+3620+
+1700+=+1700+
OK