00:01
Hi, i'm david and i'm here to have you and change your question.
00:02
Now let me bring up your question here.
00:05
In the question here, we are going to discuss about the central limit theorem.
00:10
The theorem says that if one the n greater equal to the 30, and then the sum of mean x -pal could be approximately to the normal in such the way that if the x -bile will minus the mean of a sigma divided by square of n, we have 10 the standard normal.
00:23
In this question here, we are given the mean, mu, it is, is equal to the 10 and the standard division equal to 8.
00:35
The sumper size n equals to 100, so it's greater than 20 already.
00:40
Now the question asked you to find the probability that the sum of mean x bar will be lower than 9.
00:47
To find this probability, i need to convert the xx into the z by applying the formula here.
00:53
And then we get equal to the 9 and minus the mean will be the 10, over the standard division equal to 8 the 100 and it will compute 100 and the z smaller than minus 1 10 equal to the minus 1 1 .25...