Hertz Rent-a-Car must measure the mean gas mileage achieved by its rental cars. The data below is generated for the entire fleet of 24 cars. The 5 boxed numbers constitute a randomly drawn sample....

Hertz Rent-a-Car must measure the mean gas mileage achieved by its rental cars. The data below is generated for the entire fleet of 24 cars. The 5 boxed numbers constitute a randomly drawn sample.

21 40    35    34    34    25    38    30    26     34    28     33    37    29    32      81    29    35    28    35     41    34    35   32

1. Compute the population mean(round the means to the nearest hundredth if necessary)


2. Compute the sample mean(round the means to the nearest hundredth if necessary)


3. What principle accounts for the difference? __________________________