Answer:
554 executives should be surveyed.
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 = 1.96.
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.
Standard deviation of 3 hours.
This means that
The 95% level of confidence is to be used. How many executives should be surveyed?
n executives should be surveyed, and n is found with . So
Rounding up:
554 executives should be surveyed.