Answer:
The minimum number of males over age 45 they must include in their sample is 601
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 the margin of error M as such

In which
is the standard deviation of the population(square root of the variance) and n is the size of the sample.
Assuming a variance of 1 liters, what is the minimum number of males over age 45 they must include in their sample?
This is n when 







Rounding up
The minimum number of males over age 45 they must include in their sample is 601