Hertz Rent-a-Car must measure the mean gas mileage achieved by its rental cars.
ID: 3294055 • Letter: H
Question
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 4 boxed numbers constitute a randomly drawn sample. 21 40 35 34 34 25 28 30 26 34 28 33 37 29 32 37 29 35 28 35 41 34 35 32 a. Compute the population mean __________________ (round the means to the nearest hundredth if necessary) b. Compute the sample mean ____________________ (round the means to the nearest hundredth if necessary) c. What principle accounts for the difference? __________________________
Explanation / Answer
Ans:
a)Popuation mean of entire 24 fleet cars=32.17
b)Now,take a sample of any 4 cars,
say,34,32,25,29
Mean=(34+32+25+29)/4=30
c)Sample of 4 cars does not represent the entire population,as the sample size increases,sample mean will be approximating towrads true mean of population.
1 21 2 40 3 35 4 34 5 34 6 25 7 28 8 30 9 26 10 34 11 28 12 33 13 37 14 29 15 32 16 37 17 29 18 35 19 28 20 35 21 41 22 34 23 35 24 32 Mean= 32.17