00:01
In this exercise we find a number of values from the kai squared distribution.
00:07
For part a we first want to find kai squared sub .1 comma 5.
00:17
So what this notation means is it's the kai squared distribution.
00:22
It's the kai squared value that has a significance level of 0 .1, or in other words, the area under the curve to the right of it is 0 .1.
00:30
And the second value after the comma is the degrees of freedom for the distribution.
00:35
So the kai square distribution is defined by its degrees of degrees of freedom.
00:42
So this one actually means the probability of a kai squared value being greater than i squared sub point 1 is by definition 0 .1.
00:59
So therefore the probability of a kai squared being at most this critical value is 1 minus 0 .1 which is 0 .9.
01:09
So we could solve this using software such as excel.
01:13
In excel, we can use the inverse kai square distribution function.
01:21
So that's this one.
01:25
So we enter the cumulative probability, that's 0 .9, then the degrees of freedom is the second argument.
01:30
We hit enter, we get 9 .236 approximately, or to 2 decimal places 9 .24.
01:42
The second one we want to find is kai squared 0 .1 with 30 degrees of freedom.
01:52
So we could do it in exactly the same way that we did for part a.
01:55
However, i'll show you one other function in excel.
01:59
It's the kai squared inverse right -tailed.
02:03
So this time we don't have to enter the cumulative probability, which is 0 .9.
02:06
We can just enter the significance level, 0 .1.
02:10
So we select this.
02:12
Enter 0 .1, then the degrees of freedom, in this case that's 30.
02:18
And i think i made an error here.
02:20
I need a comma.
02:22
And we get 40 .26.
02:31
And for c we want kye squared subpoint 0 .01 with 30 degrees of freedom.
02:44
Let's use the same function as we used the last time...