Answer:
The test statistic value is -0.92.
Step-by-step explanation:
In this case we need to test whether the van has an incorrect manufacturer's MPG rating.
The hypothesis can be defined as follows:
<em>H₀</em>: The manufacturer's MPG rating for the van is 54.5, i.e. <em>μ</em> = 54.5.
<em>Hₐ</em>: The manufacturer's MPG rating for the van is 54.5, i.e. <em>μ</em> ≠ 54.5.
The information provided is:
As the population standard deviation is provided, we will use a z-test for single mean.
Compute the test statistic value as follows:
The test statistic value is -0.92.
Decision rule:
If the p-value of the test is less than the significance level then the null hypothesis will be rejected.
Compute the <em>p</em>-value for the two-tailed test as follows:
*Use a z-table for the probability.
The p-value of the test is 0.36.
The p-value of the test is very large.
<em>p</em>-value = 0.36 > α = 0.01
The null hypothesis will not be rejected.
Thus, it can be concluded that the manufacturer's MPG rating for the van is 54.5 miles/gallon.