Author Question: The Pearson product-moment correlation for two variables, fear of embarrassment and anxiety just ... (Read 77 times)

jerry coleman · **on:** Jul 8, 2018

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?
a. About 0.61
b. About 61
c. About 0.78
d. About 78

Question 2

A researcher wants to select a way to measure how values in a research study are dispersed around the mean, and how homogeneous or heterogeneous they are, for a ratio-level variable. The researcher might select which of the following?

(Select all that apply.)
a. Mode
b. Range
c. Frequency distribution
d. Mean
e. Standard deviation

dajones82 · **Reply #1 on:** Jul 8, 2018

Answer to Question 1

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.

Answer to Question 2

ANS: B, E
Measures of dispersion or variability are measures of individual differences of the members of the population and sample. They indicate how values in a sample are dispersed around the mean. These measures provide information about the data that is not available from measures of central tendency. They indicate how different the scores arethe extent to which individual values deviate from one another. If the individual values are similar, measures of variability are small and the sample is relatively homogeneous in terms of those values. When there are wide variations or differences in the scores, the sample is considered heterogeneous. The heterogeneity of sample scores or values is determined by measures of dispersion or variability. The measures of dispersion most commonly reported in nursing research are range, difference scores, variance, and standard deviation. All are useful for ratio-level data.