In 2007, the United States experienced the biggest jump in food prices in 17 years (The Wall Street Journal, April 1, 2008). A variety of reasons led to this result, including rising demand for meat and dairy products in emerging overseas markets, increased use of grains for alternative fuels, and bad weather in some parts of the world. A survey compared prices (in $) of selected products at grocery stores in the Boston area. The accompanying table shows the results. Item Crosby’s Shaw’s Market Basket Two-liter Coke 1.79 1.59 1.50 Doritos chips 4.29 4.99 3.50 Cheerios cereal 3.69 2.99 3.00 Prince spaghetti 1.59 1.69 1.99 Skippy peanut butter 5.49 4.49 3.99 Cracker Barrel cheese 4.99 4.99 3.49 Pepperidge Farm white bread 3.99 3.99 3.99 Oreo cookies 4.69 3.39 3.00 One dozen eggs* 2.49 2.69 1.59 Coffee* 4.49 4.79 3.99 Gallon of milk* 3.69 3.19 1.59 In a report, use the sample information to Determine whether differences exist in the average pr
In 2007, the United States experienced the biggest jump in food prices in 17 years (The Wall Street Journal, April 1, 2008). A variety of reasons led to this result, including rising demand for meat and dairy products in emerging overseas markets, increased use of grains for alternative fuels, and bad weather in some parts of the world. A survey compared prices (in $) of selected products at grocery stores in the Boston area. The accompanying table shows the results.
| Item | Crosby’s | Shaw’s | Market Basket |
| Two-liter Coke | 1.79 | 1.59 | 1.50 |
| Doritos chips | 4.29 | 4.99 | 3.50 |
| Cheerios cereal | 3.69 | 2.99 | 3.00 |
| Prince spaghetti | 1.59 | 1.69 | 1.99 |
| Skippy peanut butter | 5.49 | 4.49 | 3.99 |
| Cracker Barrel cheese | 4.99 | 4.99 | 3.49 |
| Pepperidge Farm white bread | 3.99 | 3.99 | 3.99 |
| Oreo cookies | 4.69 | 3.39 | 3.00 |
| One dozen eggs* | 2.49 | 2.69 | 1.59 |
| Coffee* | 4.49 | 4.79 | 3.99 |
| Gallon of milk* | 3.69 | 3.19 | 1.59 |
In a report, use the sample information to
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Determine whether differences exist in the average prices of products sold at the three stores at the 5% significance level.
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Determine whether differences exist in the average prices of the 11 products at the 5% significance level.
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Determine which stores’ prices differ using Tukey’s HSD method, if it is found that differences exist in the average prices among these three stores. Use a 5% significance level.
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