Suppose the Observational Units in a Study Are Customers Arriving

Short Answer

Suppose the observational units in a study are customers arriving at a post office. For each of the following, identify whether it is a variable that can be recorded on these observational units. (No explanations are required; simply answer "yes" or "no.")
a. Gender
b. Total time spent waiting in line and being served
c. Number of customers who arrive before noon
d. Total amount of money spent
e. Whether men or women spend more money on average