Question

True or Flase

Which of the statements is true?

a. Observing an association between two variables automatically means that there is a cause and effect relationship.

b. The fact that there is a strong association between smoking and lung cancer shows that smoking actually causes lung cancer.

c. The best way to make a case for causation is to do a good experiment.

d. A strong observed association is due to direct cause-and-effect, never the effects of a lurking variable.

	1	only a and b
	2	only d
	3	only c
	4	only c and d Which of the statements is true? a. Conditional distributions provide one way to explore the relationship between the row and column variables. b. Marginal distributions provide information about the individual variables but do not provide any information about the relationship between the two variables. c. Categorical variables can be either nominal, values that have no inherent order, or ordinal, values that have an inherent order. d. A two-way table of counts (or frequencies) organizes data about two categorical variables taken from the same individuals or subjects. 1 all of them 2 only a and b 3 only a, b and c 4 only a Does regular exercise reduce the risk of a heart attack? A researcher finds 2000 men over 40 who exercise regularly and have not had heart attacks. She matches each with a similar man who does not exercise regularly, and she follows both groups for 10 years. Which of the following statements about this research is true? a. This is not an experiment because nothing is actually done to the subjects. They are just observed over time. In particular, they choose whether to exercise. b. This is a prospective study. The two groups are chosen because they differ in the suspected cause (regular exercise) of reduced risk for heart disease. We follow them forward in time to observe the outcome of interest, whether they have heart attacks. c. This is an experiment since the subjects were assigned to different amounts of exercise. d. This is a retrospective study. The two groups are chosen because they differ in the suspected cause (regular exercise) of reduced risk for heart disease. We go back in time to observe the outcome of interest, whether they have heart attacks.           1 only a and b           2 only c and d           3 only c           4 only a True or False The first step in extracting information about a relationship between two variables is to organize the raw data into a two-way table, using either pencil and paper or appropriate technology resources. Then calculate and compare different types of percentages. 1 y 2 x 3 False 4 True

Answer 1

1)

Which of the statements is true?

a. Observing an association between two variables automatically means that there is a cause and effect relationship.

b. The fact that there is a strong association between smoking and lung cancer shows that smoking actually causes lung cancer.

c. The best way to make a case for causation is to do a good experiment.

d. A strong observed association is due to direct cause-and-effect, never the effects of a lurking variable.

answer-only c

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Which of the statements is true?

a. Conditional distributions provide one way to explore the relationship between the row and column variables.

b. Marginal distributions provide information about the individual variables but do not provide any information about the relationship between the two variables.

c. Categorical variables can be either nominal, values that have no inherent order, or ordinal, values that have an inherent order.

d. A two-way table of counts (or frequencies) organizes data about two categorical variables taken from the same individuals or subjects.

answer - all of them true

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only a and b are true

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true