Question

The mean price for used cars is $10,015 . A manager of a Kansas City used car dealership reviewed a sample of 50 recent used car sales at the dealership in an attempt to determine whether the population mean price for used cars at this particular dealership differed from the national mean. The prices for the sample of 50 cars are shown in the table below.

8,297	9,485	12,534	6,897	9,414
12,155	9,399	6,899	10,367	10,077
10,553	7,033	13,168	6,478	12,518
12,864	8,504	12,868	7,709	9,036
7,106	12,652	13,032	7,153	12,111
9,415	12,848	8,800	12,460	10,963
10,951	10,860	10,119	11,176	13,110
10,403	10,410	11,943	11,453	6,220
9,693	11,641	10,601	11,791	10,309
6,402	7,994	10,383	6,849	6,564

a. Formulate the hypotheses that can be used to determine whether a difference exists in the mean price for used cars at the dealership.

b. What is the p-value? Enter negative value if your answer is negative.

Answer 1

Given:

The prices for the sample of 50 cars are shown in the table below.

8,297	9,485	12,534	6,897	9,414
12,155	9,399	6,899	10,367	10,077
10,553	7,033	13,168	6,478	12,518
12,864	8,504	12,868	7,709	9,036
7,106	12,652	13,032	7,153	12,111
9,415	12,848	8,800	12,460	10,963
10,951	10,860	10,119	11,176	13,110
10,403	10,410	11,943	11,453	6,220
9,693	11,641	10,601	11,791	10,309
6,402	7,994	10,383	6,849	6,564

Claim : The population mean price for used cars at this particular dealership differed from the national mean.

Hypothesis test :

The null and alternative hypothesis is

Ho : = 10015

Ha : 10015

So P-value is 0.9522.

Since P-value > 0.05, we fail to reject the null hypothesis.

Conclusion : There is insufficient evidence to conclude that the population mean price for used cars at this particular dealership differed from the national mean.