00:01
Once again, welcome to a new problem.
00:05
This time we're dealing with confidence interval.
00:10
We're dealing with confidence interval.
00:13
And when it comes to confidence interval, we can talk about confidence interval for means.
00:20
And under means, we have x bar plus minus the margin of error for the confidence interval, assuming we have a population standard deviation.
00:33
The margin of error is going to be z alpha over 2 times sigma of a radical n.
00:39
Sigma is the population standard deviation.
00:48
So sigma happens to be the population standard deviation and of course small n is the sample size.
00:58
Small n is the sample size.
01:00
Z a alpha over 2 is the z critical advantage and of course xba is the sample mean.
01:12
So xba happens to be the sample mean.
01:15
We're looking at a new problem and in this particular problem, we have a sample of 20 randomly selected weddings and the cost for these weddings for this particular sample happens to be 26 ,388.
01:38
It just so happens that all the weddings have a normal distribution in the population, and the standard deviation for these weddings is $8 ,200.
01:51
So we want to determine 95 % confidence interval for the main wedding costs...