The owner of a large fleet of taxis is trying to estimate his costs for next year's operations. One major cost is fuel purchases. To estimate fuel purchases, the owner needs to know the total distance his taxis will travel next year, the cost of a gallon of fuel, and the fuel mileage of his taxis. The owner has been provided with the first two figures (distance estimate and cost of a gallon of fuel). However, because of the high cost of gasoline, the owner has recently converted his taxis to operate on propane. He has measured and recorded the propane mileage (in miles per gallon) fur 50 taxis. 

a. What is the population of interest? 

b. What is the parameter the owner needs? 

c. What is the sample? 

d. What is the statistic? 

e. Describe briefly how the statistic will produce the kind of information the owner wants.