Answer:
We reject the Null and conclude that at α = 0.1, the is enough evidence to support th claim that miles per gallon has improved between 2017 and 2019
Step-by-step explanation:
This is a paired t test:
H0 : μx - μy = 0
H1 : μx - μy > 0
The test statistic :
dbar / (Sd/√n)
d = Xi - Yi
d = 2.4, 0.3, 1.7,3,-0.2, 1.1, -0.5, -3.2, 1.4, 2, 1.6, 2.2
dbar = Σd / n = 11.8 / 12 = 0.983
Sd = Σ(d - dbar)²/ (n - 1) = 1.685 (calculator)
Hence,
Test statistic = 0.983 / (1.685/√12)
Test statistic = 0.983 / 0.4864176
= 2.021
Using the test statistic score, we could obtain the Pvalue using the Pvalue FROM Tscore calculator :
Degree of freedom, df = n - 1 = 12 - 1 = 11
Pvalue(2.021, 11) = 0.03415
α = 0.1
Pvalue < α ; We reject the Null and conclude that at α = 0.1, the is enough evidence to support th claim that miles per gallon has improved between 2017 and 2019
