00:01
For this question, so we have to first of all draw a horizontal line.
00:06
Let's say we have this horizontal line here.
00:09
And there should be values.
00:11
Let's say this is zero.
00:13
So we're going to just draw the normal curve.
00:17
Let's say this is zero.
00:20
And we have negative 1, negative 2, negative 3.
00:24
We have 1, 2, and 3.
00:27
First of all, let me just copy and paste this one.
00:35
Just copy this one.
00:37
So for the first one, what we have to do? we have to find the probability of z.
00:43
So the z is negative.
00:44
So it is 2 .5.
00:46
So the 2 .5 is over here.
00:48
This is 2 .5.
00:49
And we have to get the value, which is less than this one.
00:53
So we have to get the area of this whole region here.
00:59
So this is the probability of z value, which is less than or equal to 2 .5.
01:05
But by the way, if you have the z value, that means this is a standard normal distribution, and the mean value, which is denoted by me, should be zero, and the standard division, which is denoted by sigma, should be 1.
01:20
So we can define the z random variable, normally distributive, 0 and 1.
01:25
Let's get this area, so we're going to use the normal cdf function of the calculator.
01:31
There is no lower boundary that goes to negative infinitive, so i'm going to put very small, number and the upper boundary is 2 .5 the mean is 0 standard division is 1.
01:42
Let me just press second and variance the normal cdf lower boundary i'm going to put this number and the upper boundary is 2 .5 the mean and the standard deviation so the value would be this is 0 .99 and 3 8 that is the probability that we have for the first one and what about for part b.
02:04
So for part b we have to find the probability of the z is less than one.
02:10
So i'm going to just copy and paste this one.
02:13
So the paste image.
02:14
Let me just get this image here.
02:16
So what is this? so i'm going to take the z value as one.
02:21
This is the z value.
02:22
Let's save one.
02:24
And we have to get the area of this region.
02:26
Again, we don't have any lower boundary that goes to negative infinity.
02:30
The upper boundary is one.
02:31
So we have to get the probability...