Clarifying the Concepts
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Calculating the Statistic
| Mean test grades | Students in the front | Students in the back |
|---|---|---|
| Class 1 | 82 | 78 |
| Class 2 | 79.5 | 77.41 |
| Class 3 | 71.5 | 76 |
| Class 4 | 72 | 71.3 |
Consider the following data from two independent groups:
Group 1: 97, 83, 105, 102, 92
Group 2: 111, 103, 96, 106
Consider the following data from two independent groups:
Liberals: 2, 1, 3, 2
Conservatives: 4, 3, 3, 5, 2, 4
Find the critical t values for the following data sets:
Use the following data set to answer the questions below:
15 24 35 16 18 22 16 72
For each of the following sets of data, indicate whether you would apply a square root transformation to the data and explain why you would or wouldn’t.
Applying the Concepts
Making a decision: Numeric results for several independent-
The independent-
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Sample 1: 12.6, 13.8, 11.6, 12.2, 12.1, 13.0
Sample 2: 8.5, 9.6, 10.0, 9.2, 8.9, 10.8
An independent-
Men: 28, 35, 52, 14
Women: 30, 82, 53, 61
An independent-
Men: 16,345 17,222 15,646 14,889 16,701
Women: 17,345 15,593 16,624 16,696 14,200
An independent-
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All-
Noninclusive resort guests: 3, 15, 7
An independent-
Mothers: 33, 55, 39, 41, 67
Nonmothers: 56, 48, 71
Choosing a hypothesis test: For each of the following three scenarios, state which hypothesis test you would use from among the four introduced so far: the z test, the single-
Choosing a hypothesis test: For each of the following three scenarios, state which hypothesis test you would use from among the four introduced so far: the z test, the single-
Null and research hypotheses: Using the research studies described here (from Exercise 11.33), create null hypotheses and research hypotheses appropriate for the chosen statistical test:
Independent-
Independent-
Cafeteria trays, food consumption, and an independent-
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Putting It All Together
Gender and number words: Chang, Sandhofer, and Brown (2011) wondered whether mothers used number words more with their preschool sons than with their preschool daughters. Each participating family included one mother and one child—
School lunches: Alice Waters, owner of the Berkeley, California, restaurant Chez Panisse, has long been an advocate for the use of simple, fresh, organic ingredients in home and restaurant cooking. She has also turned her considerable expertise to school cafeterias. Waters (2006) praised changes in school lunch menus that have expanded nutritious offerings, but she hypothesizes that students are likely to circumvent healthy lunches by avoiding vegetables and smuggling in banned junk food unless they receive accompanying nutrition education and hands-
Perception and portion sizes: Researchers at the Cornell University Food and Brand Lab conducted an experiment at a fitness camp for adolescents (Wansink & van Ittersum, 2003). Campers were given either a 22-