Question

Data on the fuel economy of several 2010 model vehicles are given in the accompanying table. Complete parts​ (a) and​ (b) below.

Car	mpg
1	29
2	35
3	35
4	28
5	38
6	32
7	22
8	27
9	31
10	32
11	28
12	36
13	24
14	25
15	27

​a) Find and interpret a​ 95% confidence interval for the gas mileage of 2010 vehicles. Select the correct choice below and fill in the answer boxes within your choice.

​(Round to two decimal places as needed. Use ascending​ order.)

A.One is​ 95% confident that the true mean gas mileage for cars like the ones in the sample is between __ mpg and ___mpg.

B.The true mean gas mileage for cars like the ones in the sample is between ___mpg and ___mpg​ 95% of the time.

C.​95% of all cars like the ones in the sample have gas mileages between ___mpg and ___ mpg

D.One is​ 95% confident that the gas mileage of a randomly selected car like the ones in the sample is between ___ mpg and ___ mpg

​b) Does this confidence interval capture the mean gas mileage for all 2010​ vehicles? Choose the correct answer below.

A.There is a​ 95% chance that this interval contains the true mean gas mileage for all 2010 vehicles.

B.Because the sample size is more than​ 10% of the​ population, the inferences drawn from the confidence interval are not valid.

C.Without knowing how the data were​ selected, one must be cautious about generalizing to all 2010 cars.

D.Assuming the population of 2010 gas mileages follows a Normal​ model, this confidence interval definitely captures the true mean.

Answer 1