Question

1. Claim: Carzz Magazine claims that the Civic Hybrid gets more than 38 mpg on the highway.

A random sample of 43 revealed a mean of 38.35 mpg. Use the p-value method at a 12% significance level to test the claim assuming a known population standard deviation of 3.42.

αα =
	[three decimal accuracy]
p-value =
	[three decimal accuracy]
	Conclusion
	Fail to Reject H0H0 Reject H0

Answer 1

Here we have to check the claim that Carzz Magazine claims that the Civic Hybrid gets more than 38 mpg on the highway.

We consider the following hypothesis-

H₀: µ = µ₀ vs H₁: µ > µ₀

where,   µ is the population mean = 38

to perform the test we do the following steps in MINTAB:

1. Enter all observations in a single column.

2. Click on “Stat” then “Basic statistics” then “1-sample z”

3. Check “summarized data" option and enter the sample mean=38.35.

4. Enter the given standard deviation=3.42 value in “standard deviation”.

5. Check “perform hypothesis test” and enter the value of population mean=38 in “hypothesized mean”.

6. Click on “options” and set confidence level = 12.0 and alternative as “more than” and click OK.

            7.Click OK.

Hence we get the following output:

Test of μ = 38 vs > 38
The assumed standard deviation = 3.42

N    Mean SE Mean 12% Lower Bound     Z      P
43 38.350    0.522           38.963 0.67 0.251

Thus we see

p value= 0.251.

we know if p value <= 0.880 the null is rejected

Therefore here pvalue< 0.880 so we reh=ject the null and concude that the Civic Hybrid gets more than 38 mpg on the highway.