Answer:
The 80% confidence interval for the mean consumption of meat among people over age 23 is between 4 and 4.2 pounds.
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, find 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 mean subtracted by M. So it is 4.1 - 0.07 = 4.03 pounds
The upper end of the interval is the mean added to M. So it is 4.1 + 0.07 = 4.17 pounds
Rounded to one decimal place
The 80% confidence interval for the mean consumption of meat among people over age 23 is between 4 and 4.2 pounds.