00:01
Okay, so we're looking at ahmed took a data management test and scored 28 and one in one of the private school, the class mean of 25 and standard deviation 2 .6.
00:12
So basically what we're going to use our z score formula to find how they did in comparison to the rest of their classes.
00:19
So for ahmed, he scored a 28 with a mean of 25 and a standard deviation of 2 .6.
00:33
So his z score is going to be three divided by 2 .6, which is going to come out to a 1 .154.
00:43
For emily, she scored a 36 with a mean of 32, a standard deviation of 3 .5.
00:55
So 36 minus 2 is going to be 4 over 3 .5, giving her a 1 .143.
01:05
So, officially, ahmed scored better because his score is 1 .15 standard deviations above the mean, whereas emily is only 1 .14 standard deviations above the mean.
01:17
So using that comparison, ahmed did a little bit better.
01:21
For 19, age of population, we got normal distribution with a mean of 32 and a 2 .5 for our standard deviation.
01:28
So we want to find the number of supporters in the age between 31 and 35.
01:33
So what i'm going to do is i'm going to first find the z scores for 31 and 35.
01:37
So it's going to be 31 minus 32 over 2 .5.
01:43
And then i'm going to have 35 minus 32 over 2 .5.
01:51
So the first case we have 31 minus 32.
01:55
By 2 .5 comes out to a negative 0 .4.
02:00
The second case is going to be 35 is at 1 .2.
02:06
And next i got to go to a z.
02:08
Score table.
02:10
Z score table.
02:13
Let's find mine.
02:15
So i got to find the proportions here that each of these z scores are associated with.
02:22
So negative point four associated with a 0 .3446 proportion.
02:28
1 .2 is a 0 .88 or 1 .2 .849.
02:36
So what's in between and we're going to subtract both of those.
02:39
So we're going to be 0 .849 minus 0 .346.
02:45
So we got 0 .8849 minus 0 .346.
02:51
And that's going to be 0 .5403.
02:54
The total number then is going to be that multiplied by 6 ,258.
03:01
So there should be about 3 ,381.
03:07
Yeah, we'll round it down to that.
03:08
81 people that are in the range of 31 to 35.
03:15
Number 20.
03:19
I got to pull this up again.
03:20
Number 20.
03:22
Apply the appropriate rule and determine the probability obtaining exactly two sixes by rolling a single diet eight times.
03:28
Okay.
03:29
So we're basically looking at pulling two sixes...