Answer:
64
Step-by-step explanation:
Given that an advisor to the mayor of a large city wants to estimate, within 3 minutes, the mean travel time to work for all employees who work within the city limits.
Let X be the random variable denoting the time for employees to travel within city limit
Std dev of X
For 95% confidence interval Z critical 1.96 is used because population std dev is known
Margin of error
i.e.
where n is the desired sample size.
Simplify to get
Hence atleast 64 employees should he poll