00:01
Okay, so we've got a table of data values in the question of whether different age groups think the government should do more to solve societal problems.
00:11
And we want to see whether or not the two things are related.
00:17
So our null hypothesis is going to be that age group, or sorry, well, just age, independent of their opinion on that topic.
00:30
And the alternative hypothesis is that it's dependent.
00:35
The way we're going to test this is by a chi -square test.
00:38
And the chi -square test is done by computing the chi -square test statistic, which is the observed value minus the expected value under the null hypothesis squared, divided by the expected value and the sum of that for all the different boxes.
00:52
Now we've been given the observed values in the table.
00:54
So for example, for this box, it's 319.
00:57
For this, it's 478, and so on and so on.
01:00
The expected value then, we need the row and column totals to calculate that.
01:05
If we add up all the totals for the observed values in this row, it's 1246.
01:10
In this row, it's 822.
01:13
In this column, it's 456.
01:16
In this column, 743, 558, and 311...