00:01
In this question, we have a sample of unemployment rates in the us.
00:05
So those are the samples here, sample data here.
00:09
And you asked you compute a sample mean.
00:10
Well, the sample mean, of course, is just a 4 .2 plus all the numbers to 4 .9, divided by five, right? the five samples.
00:20
So, and that, of course, is given by, due the calculation, you found this to be given by, and i found that to be actually five.
00:28
Okay.
00:32
And then what is the sample, the sample standard deviation? well, the sample standard variation i'm going to call it s and is simply given by the square root of 1 over 5 minus 1, that's 4.
00:46
And then of course you look at the 4 .2 minus the sample mean, which is 5 squared and plus all the way to 4 .9 minus 5 squared.
00:56
And then you'll find this actually to be given by.
01:02
I found this actually to be 0 .6 .2.
01:09
So you want to arrange that the empirical rule predict approximately 95 % of the unemployment rates were at 4.
01:17
Basically you asked to construct 95 % confidence interval, right? so the general formula for 95 % confidence interval should actually be given by, you know, the, you know, it has a low limit.
01:33
The lower limit is given by the sample mean, right? so in this case, it should be 5 minus the d score correspond to the 95 % level.
01:41
That's d squared 2 .5%...