A newspaper article discussed the opening of the Whole Foods Market in Time-Warner building in New York City. The following data compared the prices of some kitchen staples at new Whole Foods Market and at Fairy supermarket situated about 25 blocks from the Time-Warner building:
|
Item
|
Whole Foods (X1)
|
Fairway(X2)
|
|
Half-gallon milk
|
2.19
|
1.35
|
|
Dozen eggs
|
2.39
|
1.69
|
|
Tropicana orange juice (64 oz)
|
2
|
2.49
|
|
Head of Boston lettuce
|
1.98
|
1.29
|
|
Ground round, 1 lb
|
4.99
|
3.39
|
|
Bumble Bee tuna, 6 oz can
|
1.79
|
1.33
|
|
Uranny Smith apples (1 lb)
|
1.69
|
1.49
|
|
Box DeCecco linguini
|
1.99
|
1.59
|
|
Salmon Steak 1 lb
|
7.99
|
5.99
|
|
Whole chicken, per pound
|
2.19
|
1.49
|
- At the 0.01 level of significance, is there evidence that the mean price is higher at the Whole Foods Market than at Fairyway supermarket?
- Interpret the meaning of p-value in (a).
- What assumption is vital to carry out the test in (a)?