00:01
So we have our values here.
00:03
And i'm going to put down what the midpoint is for each of these classes.
00:07
And so i added them together and divided by two and five.
00:09
Or find out that the distance between the low and the high was 0 .5.
00:12
So added 0 .25 to each of the low values.
00:17
And so we have 10 .2, 10 .7, 11 .2, 11 .7.
00:23
And then 12 .2.
00:24
Those are the midpoints.
00:25
And then we had frequencies of 2, 8, 6 ,000.
00:30
Three and one.
00:31
Let's move that six down there.
00:33
And so those are our frequencies.
00:35
And so we want to find our mean and our standard deviation.
00:39
I believe i'm going to double check.
00:40
Yep, sample standard deviation.
00:42
So let's estimate the mean.
00:44
And so that's going to be approximately equal to.
00:47
And by the way, the sum of these numbers, there are 20 of them.
00:50
So we're adding up 20 numbers.
00:52
And we have 10 .2, and that's going to occur twice.
00:56
And we have 10 .7.
00:58
And that's occurring eight times.
01:00
And we have 11 .2, and that's occurring six times, and 11 .7, that's occurring three times, and 12 .2 is occurring just once, and that's supposed to be a two.
01:14
There we go.
01:15
So let's find what that means.
01:18
And by the way, if you do go into your calculator, you know, i require my students to show this workout, but naturally you use your software when you can, at least to double check...