00:01
We're looking at a 90 % confidence interval for mu, and the standard deviation is unknown.
00:07
So this is unknown.
00:12
And we want to look at if we had a sample size of 10 versus a sample size of 20.
00:18
We want to know which one would be a longer confidence interval.
00:21
So let's look at this.
00:23
We know that x bar plus or minus, and when we hear we would use a t star value with 9 degrees of freedom, and then we would have whatever the sample standard deviation is and we would have divided by the square root of 10.
00:35
Over here, we would have our x bar plus or minus and we would have the t star value for 19 degrees of freedom, the standard deviation over the square root of 20.
00:47
And so this standard deviation would basically be the same for each.
00:51
No, we would have different sample sizes.
00:53
So there would be a slight variation in these, but basically the two standard deviations would be the same.
00:59
And so so we need to basically look up what these values are...
