00:01
In this question, the expected value is being asked.
00:04
So first of all, let's recall the formula for expected value, which is the probability of xi times xi.
00:10
So this gives us the probability here.
00:13
So what we need here, we need to find the probability of x, which is between those two days, which are given as 25 and 30.
00:24
So first of all, what we have to do, we have to just find the probability here.
00:34
So the given mean value, let me just take notes.
00:37
The given mean value here is, which is 28 days, so the mean, which is denoted by mu, that is 28, and the standard division, which is given as 9.
00:49
So let's say this is, so x be the random variable for the normal distribution, that is, which is 28 and 9.
01:00
So we need to find the probability of x is between, which is, so the probability that the sample mean is between 25 and 30.
01:15
So first of all, we need to get the standard division for the sample and the given n value, which is 36.
01:22
So the standard deviation for the sample mean, which is equal to the standard division of the population divided by the sample size...