00:01
So our question says find the critical value with the degree of freedom being 20 and our confidence level is 90%.
00:06
So we have a find at a critical value.
00:10
Then we have something like t alpha divided by 2.
00:13
Our degree of freedom is equals to 20 and the confidence level is actually 90%.
00:19
At a confidence level of 90%, it simply implied that our level of significance alpha is going to be 100 % minus 90 % and that gives us 10%.
00:30
So looking at this notation here, it simply implies that we are supposed to divide the alpha that is the level of significance by 2 in order to be able to get critical value.
00:41
This simply implies that the test, the supposed test for this situation of us is actually a two -tailed test.
00:50
So you are supposed to get our critical value.
00:52
So we can move directly into a distribution table to get the critical value by checking for the degree of freedom on the vertical axis and checking for 10 %.
01:01
Which is also 0 .10 on the horizontal axis of our table so let's get to use our table so these are our table we have two tails and we have one tail so we are going to be using the two tails directly so that means it would be 0 .10 at this being want to use the one tail we are going to be dividing 10 percent which is 0 .10 by so that gives us 0 .05 and then we use one tail so we want to use the two tails directly so our level of significance is 0 .10, which is this...