Chapter 23: Using Statistics to Examine Relationships

Chapter 23: Using Statistics to Examine Relationships

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE

1. Which of the following correlation coefficients shows the strongest relationship?

ANS:  B

Pearson’s product-moment correlation is represented by the letter r, and the value of the r is always between –1.00 and +1.00. A value of zero indicates no relationship between the two variables. The further the value from zero, the stronger the relationship. The number indicates the strength of the relationship, and the sign connotes whether that relationship is positive or negative (inverse). Consequently, a relationship of –.60 is exactly as strong as a relationship of .60, although one is a positive relationship and the other a negative, or inverse, one. Values greater than .50 or less than –.50 indicate strong correlations.

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2. The Pearson product-moment correlation for two variables, fear of embarrassment and anxiety just before making an oral presentation, is r = .78, with a coefficient of determination of 0.6084. This means that what percentage of anxiety just before making an oral presentation can be attributed to fear of embarrassment?

ANS:  B

One can also assess the magnitude of association by obtaining the coefficient of determination for the Pearson correlation. Computing the coefficient of determination simply involves squaring the r value. The r² (multiplied by 100%) represents the percentage of variance shared between the two variables. In other words, the coefficient of determination explains how much of the change in value of one variable can be attributed to the fluctuation in value of the other variable.

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3. What does the correlational diagram X  Y mean?

ANS:  C

Correlational analyses identify relationships or associations among variables. In the diagram, the arrow points to both variables, further confirming that one doesn’t cause the other: X is merely related to Y and nothing more.

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4. A researcher develops a new instrument for measuring adjustment to widowhood in dependents whose spouses were killed in armed conflict. The researcher’s initial instrument contains 55 items, and he wants to trim these down to 25 or 30 but doesn’t want to lose any of the main concepts. What method of statistical analysis will the researcher use, in order to pare this tool down to a manageable size without loss of content?

ANS:  D

Factor analysis is one of the statistical techniques designed to examine interrelationships among large numbers of variables to reduce them to a smaller set of variables, and to identify clusters of variables that are most closely linked together (factors).

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5. A study examines the relationship between strength of belief in previous lives (Yes, Not Sure, and No) and percentage of butterfat in milk most commonly purchased (Non-Fat, 1%, 2%, Whole). The data could be analyzed by which of the following statistical tests?

ANS:  A

If one or both of two study variables do not meet the assumptions for a Pearson’s correlation, or if the variables are scaled on an ordinal scale of measurement (rather than interval or ratio), both the Spearman rank order correlation and Kendall’s tau are more appropriate statistics. The Spearman rank-order correlation and Kendall’s tau calculations involve converting the data to ranks, thereby discarding any variance or normality issues associated with the original values.

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