00:01
We are given a profit function.
00:03
First we want to find what the weekly profit is at nine units, which is what we're currently selling.
00:11
To find that we would fill in nine for x.
00:15
That would give us .004, negative .004 times nine cubed, minus .2 times nine squared, plus 500 times nine minus 700.
00:38
To the nearest penny, that would give us $3 ,780 .88.
00:48
Next we want to find the profit that is lost if we were to drop to eight units.
00:56
So first let's figure the profit at eight units.
01:00
We would fill in eight for x.
01:03
So that's going to be negative .004 times eight cubed, minus .2 times eight squared, plus 500 times eight minus 700.
01:24
That will give us $3 ,285 .15.
01:31
But what we want is how much we lost in profit.
01:36
So take what we had found for nine units sold and subtract what we just found for eight units...