00:01
Hi, for this problem, first we want to find the 30 -20 perit present tile.
00:09
So what we do is we want to find a z score corresponding to that value.
00:17
We're going to use the inverse normal function to find a z score.
00:23
For the area, you will input .23, a mean and set a deviation of 0 .0.
00:33
And you're going to get negative 0 .739 then you use this folder to solve for x.
01:01
Plug that into the calculator you will get let me see then we'll go to 1 ,3009 .59 that's our 23 percentile next we want to find the 89 percentile and we'll use the inverse norm function the error the area will be 0 .89, mean the standard deviation was 0 and 1.
01:52
That will give you the z score of 1 .227.
02:00
And then we apply the formula x equal to mean plus z times standard deviation.
02:08
And that would be equal to this number's name.
02:22
That should be equal to, let's see.
02:33
Should be equal to 1 ,683 .13.
02:41
Next, i'm going to find the first quartile, which is the 25th percentile.
02:49
So the z score would be, let me see, if we use the inverse null function again, the area is tabby .20 .0 to meet the standard deviation.
03:08
And we give it negative 0 .64, you would like...