00:01
For this question, there is given a normal distribution and the mean value given here, which is 10, and the standard deviation of the population, which was given as 4 here.
00:11
So i can define the random variable x, which is normally distributed.
00:15
So the mean and the standard deviation.
00:17
So what do we have to find? so the first one, the probability of x is equal to x is greater than 12.
00:24
To get this probability, i'm going to use the graphing display calculator application, normal cdf, lower boundary 12.
00:29
There's no upper boundary, but very big number.
00:34
So the mean is 10 and the standard division is 4 here.
00:37
Press second, variance, and the normal cdf, lower boundary, which is 12.
00:41
The upper boundary is 1.
00:43
This is second, e99, and the mean is 10, and the standard division is 4.
00:48
So the probability would be, which is 0 .30 and 85.
00:54
And for the second question, so we need to get the probability of x, which is less than 8.
00:59
Again, i'm going to use the normal cdf function.
01:03
In this case, the lower boundary is negative 1, e99.
01:06
That means negative 10 to the power 99.
01:08
So the upper boundary is 8, and the mean is 10, and the standard division is 4.
01:13
Press second, variance, the normal cdf, lower boundary, negative 1.
01:17
This is second, e99...