1. The director of marketing for a company manufacturing laundry detergent conducts an experiment to compare satisfaction with the laundry detergent product based on level of temperature used for the wash. A random sample of 500 individuals who agree to participate in the experiment is asked to use the product on a standard-sized load under a low - temperature setting. A second random sample of 500 participants is asked to use the same product on a standard - sized load under a high - temperature setting. Of the 500 participants who use the low - temperature setting, 280 are happy with the cleansing outcome. Of the 500 participants who use the high - temperature setting, 320 are happy with the results.
At the 0.05 level of significance, is there evidence that the detergent is significantly more preferred when used with the high - temperature setting than with the low - temperature setting
2)A human resources director decided to investigate employee perception of the fairness of two performances evaluation methods. To test for the differences between the two methods, 160 employees were randomly assigned to be evaluated by one of the methods: 78 were assigned to method 1, where individuals provide feedback to supervisory queries as part of the evaluation process; 82 were assigned to method 2, where individuals provide self-assessments of their work performance. Following the evaluations, employees were asked whether they considered the performance evaluation fair or unfair. Of the 78 employees in method I, there were 63 fair ratings. Of the 82 employees in method 2, there were 49 fair ratings.
Using a 0.05 level of significance, is there evidence of a significant difference between the two methods in the proportion of fair ratings?
3) A newspaper article discussed the opening of a Whole Foods Market in the Time -Warner building in New York City. Thefollowing data (stored in the fileWHOLEFOODS 1) compared the prices ofsome kitchen staples at the new WhileFood Market and the Fairway super -market located about 15 blocks form theTime - Warner building.
At the 0.01 level of significance, is thereevidence that the mean price is higher atWhole Foods Market than at the Fairwaysupermarket?
Item Whole Foods Fairway
Half - gallon milk 2.19 1.35
Dozen eggs 2.39 1.69
Tropicana orange juice (64 oz.) 2.00 2.49
Head of Boston lettuce 1.98 1.29
Ground round, 1 lb. 4.99 3.69
Bumble Bee tuna, 6 oz. can 1.79 1.33
Granny Smith apples (1lb.) 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
4) Can students save money by comparison shopping at Amazon.com? To investigate this possibility, a random sample of 15 textbooks used during a recent semester at Miami University was selected. The prices for these textbooks at both a local bookstore and through Amazon.com were recorded. The prices for the textbooks, including all relevant taxes and shipping are as stated below. At the 0.01 level of significance, is there evidence of a difference in the median price of textbooks between the local bookstore and Amazon.com?
Book Name Book Store Amazon
Principles of Microeconomics 120.00 101.22
Calculus: Early Transcendentals 137.50 115.33
Exploring Wine 65.00 37.05
Manual de Gramatica 82.75 71.36
Deviant Behavior 90.00 83.00
Modern Architecture Since 1900 39.95 26.37
Rise of Christianity 40.00 26.40
Commercial Banking 120.00 108.99
A Romance of a Republic 25.00 14.99
Chemistry in Context 133.75 102.30
Universal Principles of Design 40.00 26.40
In Mixed Company 79.50 68.76
International Marketing 154.75 126.15
Russia & Western Civilization 30.95 31.95
Enterprise Information Systems 155.75 126.97