00:01
Hello, welcome to this lesson.
00:02
In this lesson, we'll find the mean and standard deviation of the sample data.
00:07
So the first thing that we'll do here is that we'll find the probability of x, which is essentially equals to the f of x on summation f of x.
00:26
Then after that, we'll need x times the probability of x.
00:32
Then the last part we need, x minus the mean of x, alright, times itself, then times the probability of x so that we can use this to find the standard deviation.
00:53
So let's find all the required probabilities.
00:57
First of all, we need to sum this, which we have 51.
01:05
Now with 51, we divide all the x values by all the f of x values by 51.
01:15
So for example, 15 divided by 51, we leave it to three decimal places.
01:24
We have 0 .294.
01:28
Now we have 4 divided by 51.
01:31
We have 0 .078.
01:36
The 9 divided by 51, we have 0 .176.
01:43
19 divided by 51, we have 0 .373.
01:51
Finally, 4 divided by 51, which we have 0 .078.
01:59
The next part we multiply the x values by the probability of x, which is this.
02:08
So we have 1 times 0 .294, which is 0 .2.
02:15
Then 2 times 0 .078, that is this times that.
02:24
So we have 0 .156.
02:27
Then 3 times 0 .176 which is 0 .528.
02:39
Now 4 times 0 .373 which is 1 .492...