Question

Each of three supermarket chains in the Denver area claims to have the lowest overall prices. As part of an investigative study on supermarket advertising, a local television station conducted a study by randomly selecting nine grocery items. Then, on the same day, an intern was sent to each of the three stores to purchase the nine items. From the receipts, the following data were recorded. At the 0.010 significance level, is there a difference in the mean price for the nine items between the three supermarkets?

Item	Super's			Ralph's			Lowblaw's
1	$	3.52		$	5.17		$	1.25
2		2.22			5.05			2.40
3		4.15			4.36			1.80
4		3.08			4.36			1.87
5		2.40			4.15			2.10
6		5.05			3.75			3.10
7		4.15			3.75			2.50
8		4.21			4.21			2.30
9		1.57			2.10			1.14

  Click here for the Excel Data File

1. State the null hypothesis and the alternate hypothesis.

For Treatment (Stores): Null hypothesis

1. H₀: μ₁ ≠ μ₂ ≠ μ₃

2. H₀: μ₁ = μ₂ = μ₃

• a

• b

2. Alternate hypothesis

• H₁: There is no difference in the store means.

• H₁: There is a difference in the store means.

3. For blocks (Items):

1. H₀: μ₁ = μ₂ = ... μ₉

2. H₀: μ₁ ≠ μ₂ ≠ ... μ₉

• a

• b

4. Alternate hypothesis

• H₁: There is no difference in the item means.

• H₁: There is a difference in the item means.

5. What is the decision rule for both? (Round your answers to 2 decimal places.)

6. Complete an ANOVA table. (Round your SS, MS to 3 decimal places, and F to 2 decimal places.)

7. What is your decision regarding the null hypothesis? The decision for the F value (Stores) at 0.010 significance is:

• Reject H₀

• Do not reject H₀

8. The decision for the F value (Items) at 0.010 significance is:

• Reject H₀

• Do not reject H₀

9. Is there a difference in the item means and in the store means?

Answer 1