Answer:
we will fail to reject the null hypothesis and conclude that there is insufficient evidence to support the claim that the jeep has an incorrect manufacturer's MPG rating
Step-by-step explanation:
We are given;
Population mean; μ = 31.2
Sample mean; x¯ = 31.4
Sample size; n = 230
standard deviation; σ = 2.5
Significance level = 0.05
Let's define the hypotheses;
Null hypothesis; H0: μ = 31.2
Alternative hypothesis; Ha: μ ≠ 31.2
Formula for the test statistic is;
z = (x¯ - μ)/(σ/√n)
z = (31.4 - 31.2)/(2.5/√230)
z = 0.2/0.4564
z = 0.44
From online p-value from z-score calculator attached and using;
z = 0.44; two tailed hypothesis; significance value = 0.05
We have;
P-value = 0.659937
This p-value is greater than the significance value and thus, we will fail to reject the null hypothesis and conclude that there is insufficient evidence to support the claim that the jeep has an incorrect manufacturer's MPG rating
