00:01
In this case, they give us the monthly returns of financial service, and they tell us it has a mean of 10 ,000 and a standard of $75 ,000, and they want to know what are the boundaries of the middle 80 % of the monthly returns.
00:15
So an easy way to do this is to draw the distribution.
00:19
So we're going to draw the bill.
00:24
And we want to find is the middle 80%.
00:27
The middle 80 % of this bill.
00:32
Basically when the mean is 10 ,000 and the standard deviation is 75.
00:42
So we know that the standard deviation is the symbol sigma.
00:48
So we know that the lower value is going to be a little less than 10 ,000, and the upper value a little above 10 ,000.
00:57
So to do this, one easy way to do it is with your graphical calculator...