Answer to Question 1
The factors that influence the statistical choice are (1) type of measurement, (2) the nature of the comparison, and (3) the number of groups to be compared. For nominal level measurement of independent and dependent variables, cross-tabulation with the 2 statistic is appropriate. In this example, gas mileage is the dependent variable, which is not likely to be measured using a nominal scale, although it could (e.g., poor, good, excellent). More likely, examining gas mileage would be measured with a ratio measure (e.g., numbers of miles per gallon), and independent variable measures could be a mixture of ratio measures (e.g., weight of vehicle) and dummy-coded measures (e.g., hybrid or fossil-fuel), so multiple regression would likely be the most appropriate. However, if one is merely examining hybrid vs. fossil fuel, an independent samples t-test is appropriate.
Answer to Question 2
B
The world of e-commerce has beckoned the Orange County, California, chapter of Goodwill and business is booming. Four years ago, the information technology staff set up Goodwill's first web e-commerce site. The website, which is set up as sort of an eBay clone, services over one-hundred separate Goodwill organizations from around the country. Just about everything from cars to jewelry is sold on the site. About 6,000 items a day are listed. Sales have passed the 20 million mark, and revenues are running at close to 600,000 per month.
Interaction web of factors that might influence locust population size.
Factors that Influence Pulse Rate
The excitatory and inhibitory signals that directly influence the activity of a motor neuron.
Risk Factors for Cardiovascular Disease
Other Endocrine Tissues and Organs, Eicosanoids, and Growth Factors
Biology multiple choice questions