00:01
We have some data here, the robbery rate for 16 states.
00:04
We want to work out the range, variance and standard deviation.
00:08
We'll start the range.
00:10
So to get the range of a data set, all you need to do is find the largest piece of data, the max, and subtract the minimum piece of data.
00:20
So here, the largest piece of data is maryland with a very impressive 256.
00:28
The minimum is 20 .3.
00:35
From idaho.
00:42
So the range there is 200 and 35 .5.
00:50
Next, we need the variance standard deviation.
00:54
So the standard deviation is just the square root of the variance, but to get the variance in the first place, we need the mean.
01:02
To get the mean, you take all of your data points, add all of them up, divide by the number of pieces of data.
01:11
So n here is 16.
01:14
Let's add these up for a sum of 1799 .1 over 16.
01:24
If this is nice, i'll write it out.
01:27
It's not very nice.
01:27
I'm just going to leave it like this.
01:29
And we'll just call this x bar...