Question

bubbas auto owns three 1987 ford broncos—one black, one brown, and one camo—each with four - wheel drive and a standard transmission. bubba wants to test whether different types of gasoline affect fuel efficiency. in each trial, 2 gallons of gas were added to an empty tank, and the bronco was driven until the fuel was completely used. the table below shows the number of miles driven in each trial. test the data at the .05 significance level to answer the following questions. you will use this data for all 8 quiz questions.

	black	brown	camo
premium unleaded	17	19.4	20.7
ethanol	19.2	20.2	21.2
bubbas fuel blend	20.3	18.6	20.4

question 1
18.75 points
in examining the difference among the types of gasoline, what is the null hypothesis?
a (h_0:mu_1>mu_2>mu_3>mu_4)
b (h_0:mu_1<mu_2<mu_3)
c (h_0:mu_1 = mu_2=mu_3=mu_4)
d (h_0:mu_1=mu_2=mu_3)

Explanation:

In an ANOVA (Analysis of Variance) - like situation where we are testing if different types of gasoline affect fuel - efficiency, the null hypothesis assumes that there is no difference in the population means of the fuel - efficiency for different types of gasoline. Here, we have 4 types of gasoline (Unleaded, Premium Unleaded, Ethanol, Bubba's Fuel Blend), and the null hypothesis is that the population means of miles driven per 2 - gallon fill for each type are equal.

Answer:

C. $H_0:\mu_1=\mu_2=\mu_3=\mu_4$