Question

A consumer research firm would like to study whether there is a difference in average prices for health supplements at four different retail outlets in a large Midwestern city. The firm believes that the supplement sampled could affect price, so the same nine (9) supplements were selected at each of the 4 retail outlets and the prices for each supplement recorded. (Recall that when we believe the sampled units can introduce a source of variation that can affect the primary hypothesis of interest, we control for that variation using a special type of ANOVA). The following data show the prices, in dollars, for the health supplements at the four retail outlets being studied. Supplement Rite-Aid CVS Walgreens Walmart Caltrate + D (60 tablets) 8.49 7.99 5.99 5.99 Centrum (130 tablets) 9.49 9.89 7.97 9.47 Cod Liver Oil (100 tablets) 2.66 1.99 2.69 2.59 Flintstones Children's (60 tablets) 7.69 5.99 6.29 5.99 Folic Acid (250 tablets) 2.19 3.74 2.69 2.49 One-A-Day Scooby (50 tablets) 7.49 6.49 6.49 5.99 Vitamin B-12 (100 tablets) 3.59 1.99 1.99 1.79 Vitamin E (100 tablets) 4.69 2.99 3.29 3.49 Zinc (100 tablets) 2.66 3.99 2.79 2.59 What type of ANOVA design should be used in this study (Circle your answer)? Single-Factor ANOVA Randomized Block Design ANOVA Run the appropriate ANOVA test for this study. Show your ANOVA table below. Clearly label the source of variation due to blocks and due to the treatment factor (retail effect). At Î± = 0.05 level of significance can the consumer research firm conclude that there is a Retail Outlet effect? That is, can the consumer research firm conclude that there is a difference in the average prices paid for health supplements due to the type of retail outlets? Support your decision by showing the calculated and critical values of the test statistic. Is there a significant difference between the average prices for health supplements between Rite-Aid and Walgreens? Justify your answer.

A consumer research firm would like to study whether there is a difference in average prices for health supplements at four different retail outlets in a large Midwestern city. The firm believes that the supplement sampled could affect price, so the same nine (9) supplements were selected at each of the 4 retail outlets and the prices for each supplement recorded.
(Recall that when we believe the sampled units can introduce a source of variation that can affect the primary hypothesis of interest, we control for that variation using a special type of ANOVA). The following data show the prices, in dollars, for the health supplements at the four retail outlets being studied.

Supplement Rite-Aid CVS Walgreens Walmart
Caltrate + D (60 tablets) 8.49 7.99 5.99 5.99
Centrum (130 tablets) 9.49 9.89 7.97 9.47
Cod Liver Oil (100 tablets) 2.66 1.99 2.69 2.59
Flintstones Children's (60 tablets) 7.69 5.99 6.29 5.99
Folic Acid (250 tablets) 2.19 3.74 2.69 2.49
One-A-Day Scooby (50 tablets) 7.49 6.49 6.49 5.99
Vitamin B-12 (100 tablets) 3.59 1.99 1.99 1.79
Vitamin E (100 tablets) 4.69 2.99 3.29 3.49
Zinc (100 tablets) 2.66 3.99 2.79 2.59

What type of ANOVA design should be used in this study (Circle your answer)?
Single-Factor ANOVA
Randomized Block Design ANOVA

Run the appropriate ANOVA test for this study. Show your ANOVA table below. Clearly label the source of variation due to blocks and due to the treatment factor (retail effect).

At Î± = 0.05 level of significance can the consumer research firm conclude that there is a Retail Outlet effect? That is, can the consumer research firm conclude that there is a difference in the average prices paid for health supplements due to the type of retail outlets? Support your decision by showing the calculated and critical values of the test statistic.

Is there a significant difference between the average prices for health supplements between Rite-Aid and Walgreens?
Justify your answer.

Added by Larry H.