We would like to estimate the true mean number of hours adults sleep at night. Suppose that sleep time is known to follow a Normal distribution with standard deviation 1.5 hours. For a sample of 12, what is the margin of error for a 95% confidence interval

The margin of error for a 95% confidence interval is 0.8487 hours of sleep.

Step-by-step explanation:

We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of .

So it is z with a pvalue of , so

Now, we find the margin of error M as such

In which is the standard deviation of the population and n is the size of the sample.

For a sample of 12, what is the margin of error for a 95% confidence interval

The margin of error for a 95% confidence interval is 0.8487 hours of sleep.

step-by-step explanation: 2