Relationship Coefficients

Correlation coefficient is the statistic that measures the strength and direction of a linear association between two quantitative variables.

• True

• False

If r is positive, then there is...

• Negative association

• No correlation

• Positive association

If r=0 , then there is...

• Negative association

• No correlation

• Positive association

Which of the following statements is true?

• The correlation coefficient and the slope of the regression line may have opposite signs.

• A correlation of 1 indicates a strong relationship between the variables.

• Correlations of +0.87 and -0.87 indicate the same degree of clustering around the regression line.

• A correlation of 0 shows little or no association between two variables.

Correlation coefficients are:

• A point that does not fit the overall pattern.

• A histogram.

• A numerical measure of the direction and strength of a linear association.

• A graphical display.

A study compared the number of cars a person owns and that person’s average yearly salary. It was determined that the relationship between these two quantities was linear and the correlation was 0.37. Which conclusion can be made on the findings of this study?

• There was a weak relationship.

• There was a strong relationship.

• There was no relationship.

• Unpredictable.

Which of the following is true for correlation coefficients?

• x is the explanatory variable and y is the response variable.

• x is the response variable and y is the explanatory variable.

• The choice of x and y as the explanatory and response variables does not matter.

If r is negative, then there is...

• Negative association

• No correlation

• Positive association

r = -0.3 is considered to have...

• moderate negative correlation

• weak negative correlation

• no correlation

• strong negative correlation

What is most likely the correlation coefficient for this data set?

• r = -0.20

• r = -0.70

• r = 0.83

• r = 1.00