00:01
In this question, we're going to use linear interpolation to estimate the desired quantity.
00:05
A vending company estimates that f of x cans of soft drink can be sold in a day if the temperature is x degrees fahrenheit as given in the table.
00:14
We're going to estimate the number of cans that can be sold first at 72 degrees and then at 94 degrees.
00:22
So first, let's consider the 72 degrees.
00:26
That's between x equals 60 and x equals 80.
00:29
So i'm going to look at my slope on that interval from 60 to 80.
00:34
I'm going to say that my slope is equal to y2 minus y1, so 120 minus 84 over x2 minus x1.
00:43
That's 80 minus 60.
00:45
Now, 120 minus 84, that's equal to 36.
00:51
So i'm going to have 36, and that's divided by 20, which simplifies to 1 .8.
00:59
So that's my slope between x equals 60 and x equals 80.
01:03
Now, i'm going to write the equation of the line connecting those points in point slope form.
01:08
I'm going to say i have y minus a y -coordinate.
01:12
Y minus 84 is equal to my slope, 1 .8, times the quantity of x minus the x -coordinate, which is 60.
01:22
Now, suppose that my x is 72.
01:27
I would have y minus 84 equals 1 .8 times the quantity of 72 minus 60.
01:36
So now i'm going to head to my calculator.
01:38
I've got 72 minus 60.
01:41
That's certainly 12...