Answer:
C.25
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 the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
Which of the following is the smallest sample the company can take to achieve the desired margin or error?
This is n when







We have to round up.
So the correct answer is:
C.25