Answer:
The 99% confidence interval for the mean distance from home to work for all residents of this state is between 8.49 and 9.19 miles.
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 Z-table as such z has a p-value of .
That is z with a pvalue of , so Z = 2.575.
Now, 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.
The lower end of the interval is the sample mean subtracted by M. So it is 8.84 - 0.35 = 8.49 miles.
The upper end of the interval is the sample mean added to M. So it is 8.84 + 0.35 = 9.19 miles.
The 99% confidence interval for the mean distance from home to work for all residents of this state is between 8.49 and 9.19 miles.