00:01
Okay, for the first four, we're looking at a mounted distribution.
00:05
So we can use our z scores with the table to find out our probabilities.
00:10
So to find our z scores, we're going to take the mean, the data point, excuse me, minus the mean over the standard deviation.
00:19
So i'm going to do that for each one of these values here that are given.
00:23
So i'm going to say for 45, we're going to have a z score.
00:26
We're going to say our 45 minus 60 over 50.
00:31
And then i'm going to do the same thing for 75, 75 minus 60 over 15.
00:37
And i see that's going to be negative 1, and that's going to be 1.
00:41
So i need to, i'll have to go to my z table and find the z scores for negative 1 in 1, or the values.
00:48
So for negative 1, i happen to be right on it.
00:51
That's going to be 0 .15866.
00:57
Now let me go find it for 1.
01:01
1 .844.
01:04
And to get our answer, we simply subtract those and we'll have our answer.
01:09
I'll go do those subtractions in a minute.
01:11
For the next one, we need to find the score for 54 .3.
01:15
So i'm going to say 54 .3 minus 40 over that standard deviation of 14.
01:21
So i'm going to find my calculator here.
01:24
Let me get it.
01:25
I've got it right here.
01:26
And i'm going to do that on my calculator, minus 40.
01:30
And then we'll divide that by 14, and i get a z score of 1 .02.
01:37
So i'm going to go find 1 .02 on my table, and i see 0 .84614.
01:47
And since that's greater than, we're going to get our answer by subtracting from 1.
01:52
So again, we'll go to our calculator in a little while.
01:54
Let's do the same thing here...