00:01
So we want to find a 90 % confidence interval for the standard deviation.
00:08
So we'll need to, since our sample size is 10, we'll have 9 degrees of freedom.
00:14
And we'll want to have .05 in the upper tail, .05 in the lower tail.
00:21
So this will be .95.
00:23
And looking at my table with 9 degrees of freedom for those values, i have an online table that i'm looking up.
00:30
And for 9 for the upper is 16 .919.
00:37
And that lower one is, so for .95 is 3 .325.
00:50
And so we have n minus 1 times the variance.
00:56
So i'm just going to write that value down, s squared.
01:00
And then we divide that by the larger value for the left endpoint.
01:06
And that would be for variance...