Question

1.   Does the mean cost of a 1999 Honda Civic differ by location? To answer this question, a researcher with a lot of free time collected data on recent sales of these cars for four major cities, which is shown in the table below.

Portland	Seattle	San Fran	Baltimore
4998	5878	3977	3546
5341	5393	5105	4310
4875	4764	4779	4052
5127	4805	4006	3037
6861	6325	5248	3828
5745	5888	4000	4225
5793	6752	4462	4045
5043	5546	4346	3649
4738	5149	5104	3165
4276	5588	6306	4995

Notice: It’s 10 cars for each city. They’re not in any particular order.

Calculations notes
You’re going to go through the calculations to find the p-value from the data, but you can check all the calculations by using Excel, a calculator, or something else.
The calculations for this module are way more complicated than we’ve seen before, so please ask if you’re not sure. There’s also an Excel file on D2L where you can see the formulas to see where each number comes from.

a.   Write hypotheses appropriate to test the question here.

b.   A comparison boxplot of the prices is shown below. Based on the boxplot, does it appear the mean selling price for the cars is the same for every city? Explain your answer with evidence from the boxplot.

c1.   Calculate the mean price for each city.
c2.   Calculate the variance of the means.
c3.   Multiply that value by 10 to get the MST. (10 because its 10 observations / city.)
d1.   Calculate the variance in price for each city.
d2.   Calculate the mean of the variances. This is the MSE.
e.   Calculate the F-ratio as F = MST/MSE
f.   To calculate the p-value, we need the numerator df and the denominator df. What are those?
g.   What is the p-value for the test?
h.   Based on your p-value, make a conclusion with the context of this situation.

Answer 1

Hence, we can conclude that prices of HONDA CIVIC differes from CITY to CITY.