Reading Quiz CH8 Flashcards Preview

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Flashcards in Reading Quiz CH8 Deck (8)
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1
Q

The numerical coefficient that is used to indicate the the extent to which two variables are related, or associated, is called which of the following?

A

Pearson’s product moment correlation coefficient

2
Q

A perfect positive correlation would result in a coefficient equal to _________ whereas a perfect negative correlation would result in a coefficient equal to ______.

A

+1.00 and -1.00, respectively

3
Q

True or False: Cause and effect may be present in a relationship between two variables; however, correlation does not prove causation.

A

True

4
Q

When attempting to visually assess the degree to which two variables might be related to one another, producing which of the following plots would be most appropriate?

A

Scatter Plot

5
Q

Which of the following are true in regard to the best fit line?

A

a. It represents the best linear estimate of the relationship between two variables, b. Generally speaking, the best fit line for a positive relationship will slope upwards (from left to right), whereas the best fit line for a negative relationship will slope downwards (from left to right) c. If the relationship between two variables was zero (r = 0.00), the slope of the best fit line would also be zero (meaning that the line would be perfectly horizontal or vertical); All of the above are true

6
Q

If we ran a correlation analysis and found that two variables were correlated at r = .64, how much common variance could we say is “shared” between these two variables?

A

41%

7
Q

If we ran a correlation analysis and found that 82% of the variance in variable Y could be explained by (or is shared with) the variance in variable X, what percentage of the variance in variable Y must be left unexplained? (Enter as a percentage; e.g. 10%)

A

18%

8
Q

What determines whether or not our data have violated the assumption of homoscedasticity?

A

If we plotted our residuals and found that the variance of the residuals does vary (not constant), we would determine that we have violated the assumption of homoscedasticity.