00:02
Okay, so we have the z score here and the z score here, and we want to know the proportion between the mean and the z score.
00:21
So the means always in the middle here.
00:30
So mean, mean is zero, and then 1 .71 might be about there.
00:46
Sorry, one seven, not seven one.
00:49
And so we're going to find this area here.
00:56
Now, to find that, we're going to use the table and we're going to do some subtraction.
01:03
Okay? because our table, let me grab that real quick.
01:09
Our table does less than, okay, and only less than.
01:15
And so in order to go through and calculate our in -between part, we're going to find the amount for less than zero and the amount for less than 1 .17.
01:32
And then we're going to subtract.
01:35
Okay, so let's find 1 .17 first.
01:40
So 1 .1.
01:42
So i go on this side of the table.
01:44
See the z is here.
01:46
That means the zs are on the outside.
01:47
And go to 1 .1.
01:49
Okay, here's 1 .1.
01:51
And now my third digit, my 100th place, is 7.
01:55
So here is 1 .17 .879.
02:03
0 .8790.
02:10
Okay, so i'm going to do 0 .0.
02:14
See, and now i forgot what it was.
02:17
Just a second, sorry.
02:20
1 .17 -8790.
02:29
8790.
02:30
So that's the table for that one.
02:32
Minus.
02:33
Now, i can go and i can look up on the table zero, but i don't need to because i know that's the mean.
02:39
So i know below the mean is always 50%.
02:44
So this is going to be 0 .50.
02:50
Okay? so then i subtract those and i get 0 .33790.
03:04
And that is the amount of area in between 0 and 1 .17.
03:12
So now let's say 0 and negative 1 .37.
03:20
That's probably a little low, but we're still doing between.
03:26
And this time 0 is going to be the biggest.
03:28
So we're going to do 0 .5 minus.
03:33
Now i'm going to go back to my table, 1 .37.
03:38
Negative this time negative 1 .3 .0, 1, 2, 3, 4, 5, 6, 7.
03:48
So this is my column for my 7s.
03:51
Yep, just doubling and making sure.
03:55
Negative 1 .37 is 0 .0853.
04:08
Okay.
04:10
And then i just subtract those.
04:14
And that's going to leave me with an area of 0 .41, 47.
04:19
And remember, you can turn those into percent by just moving the decimal over two places.
04:25
And so this will be 41 .47%.
04:30
Okay.
04:32
So then number five talks about a test given to seventh graders in new mexico, gives the mean and the standard deviation, and gives paul score and christine's score...