1 Classify each as nominal-level, ordinal level, interval-level, or ratio-level data.
a.time needed for racing cars to make a practice drive _____________________
b. horsepower of automobile engines ___________________________________
c. salaries of cashiers at Acme supermarkets _____________________________
d. rankings of similar products by Consumer Reports ______________________
e. pages in books at a local library _____________________________________
2. Classify each variable as discrete or continuous.
a. lifetimes of batteries in caller ID’s ___________________________________
b.number of votes for a political candidate ______________________________
c.incomes of professional baseball players ______________________________
d.water temperatures of the Atlantic Ocean ______________________________
e.heights of professional basketball players ______________________________
3.Classify each sample as random, systematic, stratified, or cluster.
a. every tenth light bulb is tested as working/defective ______________________
b.seven geographic regions of the USA are defined and all registered voters in two randomly selected regions are sampled ________________________________
c.seven geographic regions of the USA are defined and 1000 registered voters in those regions are randomly sampled __________________________________
d.American households are selected by random numbers to determine occupants preferences in television viewing ____________________________________
e. Every 100th tax return is selected for audit _____________________________
4.Explain why the claims of these studies might be suspect.
a. The average salary of the graduates of the class of 1980 is $32,500.
b. It is estimated that in Podunk there are 27,256 cats.
c. Only 3% of the men surveyed read Cosmopolitan magazine.
d. Based on recent mail survey, 85% of the respondents favored gun control.
e. A recent study showed that high school dropouts drink more coffee than students who graduated; therefore, coffee dulls the brain.
f. Since most automobile accidents occur within 15 miles of a person’s residence, it is safer to make long trips.
5. Identify the independent variable(s) and the dependent variable for each:
a. Subjects were randomly assigned to two groups, and one group was given an herb and the other group a placebo. After 6 months, the numbers of respiratory tract infections each group had were compared.
b. A researcher stood at a busy intersection to see if the color of an automobile a person drives is related to running red lights.
c. A researcher finds that people who are more hostile have higher cholesterol levels than those who are less hostile.
d. Subjects are randomly assigned to four groups. Each group is placed on one of four special diets a low-fat diet and high-fish diet, a combination of low-fat diet and high-fish diet, and a regular diet. After 6 months, the blood pressures of the groups are compared to see if diet has any effect on blood pressure.