Null hypothesis, Ho: μ Winco -μ ?Walmart? ≥ 0

Alternative, Ha: μ Winco?? -μ ?Walmart ??< 0

WinCo Foods, a large Discount grocery retailer in the western United States, promotes itself as the lowest priced grocery retailer. In newspaper ads WinCo Foods published a price comparison for products between WinCo and several competing grocery retailers. One of the retailers compared against WinCo was Walmart, also known as a low price competitor. WinCo selected a variety of products, listed the price of the product charges at each retailers, and showed the sales receipt to prove the prices at WinCo were the lowest in the area. A sample of the products and their prices comparison at both WinCo and Walmart are shown in the following table: 

Item.....Winco.....Wal Marg

Bananas.....0.42.....0.56

Red Onions......0.58.....0.98

Mini Peeled Carrots.....0.98.....1.48

Roma Tomatoes.....0.98.....2.67

Deli Tater Wedges.....1.18.....1.78

Beef Cube Steak.....3.83.....4.118

Beef Top Round London Boil.....3.48.....4.12

Pillsbury Devils Food Cake Mix....0.88.....0.88

Lipton Rice and Sauce Mix.....0.88.....1.06

Sierra Nevada Pale Ale.....12.68.....12.84

Gm Cheerios Oat Clusters.....1.98.....2.74

Charmin Bathroom Tissues.....5.98......7.48

Bumble Bee Pink Salmon......1.58......1.98

Pace Thick & Chunchy Salsa.....2.28.....2.78

Nalley Chili.....0.78.....0.78

Challenge Butter.....2.18.....2.58

Kraft American Singles.....2.27.....2.27

Yuban Coffee FAC.....5.98.....7.56

Totinos Pizza Rolls.....2.38.....2.42

Rosarita Refried Beans.....0.68.....0.73

Barilla Spaghett.....0.78.....1.23

Sun-Maid Mini Raisins.....1.18.....1.36

Jif Peanut Butter, Cream.....2.54.....2.72

Dole Fruit Bow.....1.68.....1.98

Progresso Chicken Noodle Soup.....1.28.....1.38

Precious Mozzarella Ball.....3.28.....4.2

Mrs. Cubbison Seasoned Crotons.....0.88.....1.12

Kellogg's Raisin Bran.....1.98.....2.5

Campbell's Soup at Hand.....1.18.....1.26