00:01
We have a mean of 365 ,000 and we have a standard deviation of 42 ,000.
00:07
We want to know the coefficient of variation, which is going to be the standard deviation divided by the mean times 100.
00:14
So let's go ahead and go 4 ,200 over 3 ,650 ,000 times 100.
00:21
I like to get rid of zeros, so get rid of those, those.
00:24
So basically we're going to take 4 ,200 divided by 365 and we'll have that coefficient to be 1 .15.
00:33
Now we want to use the empirical rule to determine the range of prices that includes 68 % of the homes and then 68 % of the homes.
00:49
Okay, that's what i'm looking at.
00:50
The z, okay, i've got to go back to my list.
00:53
The z score.
00:53
So let's get our z score for a house that's 382.
00:58
So we want to know our z score, which is going to be the data point minus the mean over the standard deviation.
01:05
So we're looking at 382 ,000 minus the mean, 365, over my standard deviation, 4 ,200.
01:13
So let's go get that number real quick, 365, and then divide that by 4 ,200.
01:20
We get a z score of 4 .05.
01:24
What's the next one we want? we want to know the range for those in the 68%, which is plus or minus one standard deviation of the mean.
01:35
So we're going to take 365 plus or minus 4 ,200...