Question

Is there a difference in the mean price for vitamins at the retail outlets provided ? Use alpha = .05.

Select one: a. Yes, the average ranges from $4.92 to $5.93 -- the range of means is very spread out. b. Yes, the sum of squared errors between stores is two times that within group - enough to reject the claim the means are equal. c. No, the F value is far less than F critical, thus we cannot reject the claim that the means are equal. d. No, the t-value comparing the difference of means is insufficiently different to reject the claim of equal means.

Additional Information:

Item	CVS	Kmart	Rite-Aid	Wegmans
Caltrate +D (600mg/60 tablets)	8.49	5.99	7.99	5.99
Centrum (130 tablets)	9.49	9.47	9.89	7.97
Cod liver oil (100 gel tablets)	2.66	2.59	1.99	2.69
Fish oil (1,000 mg, 60 tablets)	6.19	4.99	4.99	5.99
Flintstones Children's (60 tablets)	7.69	5.99	5.99	6.29
Folic acid (400 mcg/250 tablets)	2.19	2.49	3.74	2.69
One-a-Day Maximum (100 tablets)	8.99	7.49	6.99	6.99
One-a-Day Scooby (50 tablets)	7.49	5.99	6.49	5.47
Poly-Vi-Sol (drops, 50 ml.)	9.99	8.49	9.99	8.37
Vitamin B-12 (100 mcg/100tablets)	3.59	1.99	1.99	1.79
Vitamin C (500 mg/100tablets)	2.99	2.49	1.99	2.39
Vitamin E (200 IU/100tablets)	4.69	3.49	2.99	3.29
Zinc (50 mg/100 tablets)	2.66	2.59	3.99	2.79

Answer 1

We run a one-way ANOVA for the data and get the following output ...

One factor ANOVA
	Mean	n	Std. Dev
	5.932	13	2.9112	CVS
	4.927	13	2.5296	Kmart
	5.309	13	2.8504	Rite-Aid
	4.824	13	2.2945	Wegmans
	5.248	52	2.6158	Total
ANOVA table
Source	SS	df	MS	F	p-value
Treatment	9.8016	3	3.26721	0.46	.7099
Error	339.1660	48	7.06596
Total	348.9677	51

The p- value > 0.05. This also means the test statistic F is less than the critical F

Decision: Fail to reject Ho

Conclusion: There is no sufficient evidence that the means are different

You can mark option (c) as the answer.