# Correlation - Online Test

Q1. Correlation refers to
Explaination / Solution:

Correlation between two variables shows how the two series are associated with each other. How one variable changes with the change in other

Q2. If two variables are highly correlated, what do you know?
Explaination / Solution:

High degree of correlation implies that there is a strong relationship between the two variables and that the changes in one variable cause predictable changes in the other variable.

Q3. If paired scores occupy the same positions within their own distributions (high with high and low with low)
Explaination / Solution:

If high scores on one variable are paired with high scores on other variable and low scores are paired with low scores, correlation will be high and therefore Pearson's r will be high and positive.

Q4. Which of the following indicates the strongest relationship?
Explaination / Solution:

The highest score shows high degree of correlation. It can be positive or negative.

Q5. A researcher finds the value of correlation coefficient to be .40 between personal income and the number of years of college completed. Based upon this finding he can conclude that
Explaination / Solution:

A positive value of correlation coefficient implies that high value of one variable will correspond to a high value of another variable and vice versa.

Q6. Which of the following may have an adverse effect on the correlation coefficient?
Explaination / Solution:

Other factors being equal, a restricted range usually yields a smaller correlation coefficient.

Q7. Which of the following is not a use for r?
Explaination / Solution:

Power Analysis allows us to determine the sample size required to detect an effect of a given size and it does not require the use of r.

Q8. If two variables oppose each other then the correlation will be
Explaination / Solution:

Negative correlation implies that high value of one variable will correspond to a low value of another variable and vice versa.

Q9. A perfect negative correlation is signified by
Explaination / Solution:

When there is perfect negative correlation, the value of correlation coefficient will be -1.

Q10. The Spearman correlation is used with
Explaination / Solution:

Spearman's rank correlation is used for ordinal data, where the values have not been measured but have been ranked.