Question

The spreadsheet entitled Compact Cars has sales data for six of the top automobile models, over a six month period in 2018. There are no sales for the whole/complete of 2018 year sales data meaning what is available is a sample of the 2018 year sales. Your task is to test both: if the mean number of automobile types sold is significantly different for all of the six models AND whether or not the mean number of automobiles sold per month is significantly different between the months (Some these tests will be taught in a later part of the class under “Hypothesis Testing” & ANOVA). The sample of automobile sales data for 2018 is in the Excel file provided. So, first do the following tests and conclude the findings (these have been taught in class):

Project data

Month	Chevy Malibu	Ford Fusion	Hyundai Sonata	Honda Accord	Toyota Camry	VW Passat
January	21,711	21,303	21,006	19,341	20,985	19,671
February	18,274	19,385	19,992	20,872	19,785	19,105
March	17,934	16,557	15,713	17,181	16,889	16,006
April	19,387	17,420	15,054	14,500	14,093	14,083
May	17,097	16,147	15,023	15,800	15,727	16,875
June	16,244	16,173	14,295	15,058	15,236	16,893

Answer from part 1:

	Chevy Cruze	Ford Focus	Hyundai Elantra	Honda Civic	Toyota Corolla	VW Jetta
Mean	18441	17831	16847	17125	17119	17106
Median	18104	16989	15384	16491	16308	16884
Mode	0	0	0	0	0	0
Range	5467	5156	6711	6372	6892	5588
Stdev	192.85	2090.29	2881.97	2524.78	2710.96	2050.49

Part 2

1. Introduction to the problem and formulation of the business problems presented

2. Data description

3. Descriptive statistics and the supporting graphs   

4. Analyses   

5. Interpretation of results, explain the methods shortcoming (if any, if you don’t think there is shortcoming please explain why the methods are appropriate for this analyses), final conclusions which include practical decision-making

Please answer part 2.

Answer 1

For Cars:

The hypothesis being tested is:

H0: µ1 = µ2 = µ3 = µ4 = µ5 = µ6

Ha: At least one means is not equal

	Mean	n	Std. Dev
	18,441.2	6	1,923.85	Chevy Malibu
	17,830.8	6	2,090.29	Ford Fusion
	16,847.2	6	2,881.97	Hyundai Sonata
	17,125.3	6	2,524.78	Honda Accord
	17,119.2	6	2,710.96	Toyota Camry
	17,105.5	6	2,050.49	VW Passat
	17,411.5	36	2,282.95	Total
ANOVA table
Source	SS	df	MS	F	p-value
Treatment	1,08,93,072.81	5	21,78,614.561	0.38	.8577
Error	17,15,22,670.17	30	57,17,422.339
Total	18,24,15,742.97	35

The p-value is 0.8577.

Since the p-value (0.8577) is greater than the significance level (0.05), we fail to reject the null hypothesis.

Therefore, we cannot conclude that the mean number of automobile types sold is significantly different for all of the six models.

For Months:

The hypothesis being tested is:

H0: µ1 = µ2 = µ3 = µ4 = µ5 = µ6

Ha: At least one means is not equal

	Mean	n	Std. Dev
	20,669.5	6	944.53	January
	19,568.8	6	877.45	February
	16,713.3	6	808.09	March
	15,756.2	6	2,172.00	April
	16,111.5	6	772.67	May
	15,649.8	6	951.77	June
	17,411.5	36	2,282.95	Total
ANOVA table
Source	SS	df	MS	F	p-value
Treatment	13,97,38,114.14	5	2,79,47,622.828	19.65	1.17E-08
Error	4,26,77,628.83	30	14,22,587.628
Total	18,24,15,742.97	35

The p-value is 0.0000.

Since the p-value (0.0000) is less than the significance level (0.05), we can reject the null hypothesis.

Therefore, we can conclude that the mean number of automobiles sold per month is significantly different between the months.