00:01
Hi, i'm david and i'm here to have you answer your question.
00:03
Now let me bring up your question here.
00:07
Now in this question we discuss about the normal distribution where we will have a normal population with the meat equal to 100 and the standard divi and the variance sigma square equal to 25.
00:25
Therefore the sigma equals the square of the 25 and equal to 5.
00:30
Now how large must the random symbol be if you want the standard error of this sample average to be 1 .5? recounted the standard error sd, it will equal to the sigma over square letter n.
00:48
And we want the sample error equal to the 1 .5.
00:54
So it really tells us that the sigma equal to the 5 over squarely the dot.
01:00
N it must equal to 1 .5 therefore it tells us that the square n equal to 5 over 1 .5 and equal to 1 5 it will equal to the 3 .33 and therefore n equal to the 3 .33 square and then we get equal to the 11 .1 so we can round up to the 12.
01:31
So that would be the first part.
01:34
And now the second part as going to calculate the probability of the average exit 105 based on the 16 observation.
01:44
So it means then now in equal to the 16 and then 1 to 5 probability that the average with the x bar it will be greater than the 105...
