00:01
Alright, in your question, you're working on a kai squared test of independence.
00:05
You're given this table, you've already selected the appropriate hypothesis for your null and alternative.
00:13
And we need to calculate the kai squared statistic.
00:17
So what we first want to do is i added a total row and a total column to this table.
00:25
I want to add up the domestic flights, which works up to 275.
00:31
I want to add up the international, which is 640.
00:35
Then we have our total of 915.
00:38
Now i want to add the rows, which would be 47, and the next one would be 218, and the next one would be 650.
00:55
And i'm going to figure out, okay, what percent should have selected first class for each flight.
01:07
So looking at this total, i want to figure out what these percentages are, and then i'll use that in my next step.
01:19
So i'm just doing 47 divided by 915.
01:24
It's probably not going to be a nice decimal.
01:27
It's not.
01:27
So i'm going to leave it 47 over 915.
01:32
This one would be 218 over 915.
01:36
And this would be 650 out of 915.
01:41
Again, those represent basically what we should expect the distribution to be for first class, business class, and economy class.
01:50
And now we'll multiply it to the total for domestic flights.
01:55
So i'm going to take each of these times 275 to get an expected value, which i'll put in parentheses, beside each domestic number.
02:09
So i'm going 47 divided by 915 times 27.
02:16
Which would give me 14 .1257.
02:23
I'm going to round it to four decimal places for the expected amount of domestic passengers that would travel first class.
02:31
Now i'll do 218 divided by 915 times 275, and that would be 65 .5 .591.
02:49
And then the next one would be 132.
02:56
I'm sorry, not 132...