SOLUTION: Assume that the number of defective basketballs produced is related by a linear equation to the total number produced. Suppose that 9 defective balls are produced in a lot of 400,

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Question 230450: Assume that the number of defective basketballs produced is related by a linear equation to the total number produced. Suppose that 9 defective balls are produced in a lot of 400, and 19 defective balls are produced in a lot of 525.
Find the number of defective balls produced in a lot of 700 balls.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
What the problem is really asking is:
What is the straight line equation that goes
through the points (400,9) and (525,19)?
Then find the point on the line (x,y)
where y is unknown, and x+=+700
-------------------------------------------
I'll use the equation

where
x%5B1%5D+=+400
y%5B1%5D+=+9
and
x%5B2%5D+=+525
y%5B2%5D+=+19
%28y+-+9%29%2F%28x+-+400%29+=+%2819+-+9%29%2F%28525+-+400%29
%28y+-+9%29%2F%28x+-+400%29+=+10%2F125
125%2A%28y+-+9%29+=+10%2A%28x+-+400%29
125y+-+1125+=+10x+-+4000
125y+=+10x+-+2875
25y+=+2x+-+575
y+=+%282%2F25%29%2Ax+-+23
Now I can find (700,y)
y+=+%282%2F25%29%2A700+-+23
y+=+56+-+23
y+=+33
There will be 33 defective balls in a lot of 700
check answer:
y+=+%282%2F25%29%2Ax+-+23
9+=+%282%2F25%29%2A400+-+23
9+=+32+-+23
y+=+9
OK
y+=+%282%2F25%29%2Ax+-+23
y+=+%282%2F25%29%2A525+-+23
y+=+42+-+23
y+=+19
OK