00:01
So here we're talking about elasticity.
00:03
We know that the price of x is going from 6 to 4.
00:07
We know that the quantity of y is going from 30 to 40.
00:13
And we need to calculate a cross -price elasticity.
00:16
So there's two things going on here.
00:19
First of all, what is a cross -price elasticity? that's between two goods, across two goods.
00:27
So here that would be the percentage change in the quantity of y over the percentage change in the price of x.
00:35
So that is how much does the quantity of y react to the price of x? we also need to know about the midpoint percentage change.
00:43
The midpoint percentage change is equal to new minus old.
00:49
That's just the raw change over the midpoint.
00:52
So we need the midpoints here.
00:54
And the midpoints are 5 and 35.
00:58
So now we can plug in, right? we calculate.
01:02
We get the percentage change in quantity is 40 minus 30 over 35.
01:09
The midpoint percentage change in price is 4 minus 6 over 5...