Correlation Analysis Quiz

What does correlation refer to?

• The absence of correlation between variables

• The change in one variable causing a change in another variable

• The average value of a variable

• The associations between variables

What is the range of the correlation coefficient 'r'?

• 0 to 1

• -1 to +1

• Minus infinity to plus infinity

• 1 to 100

What type of correlation would be expected between a company’s expenditure on health and safety and the number of work-related accidents?

• Positive

• Negative

• None

• Infinite

If two variables are absolutely independent of each other, what is the predicted correlation between them?

• -1

• 0

• +1

• +0.1

Which correlation coefficient is the strongest: +0.65 or -0.70?

• Cannot say from the information given

• +0.65

• -0.70

• Depends on N

What is the range of values for the correlation coefficient 'r'?

• 0 to 1

• 1 to 10

• 0 to 100

• -1 to 1

What does a correlation coefficient of +1 indicate?

• No correlation

• Perfect positive correlation

• Perfect negative correlation

• Low degree positive correlation

What method is used to graphically investigate the relationship between two variables without calculating any numerical value?

• Karl Pearson’s coefficient of correlation

• Assumed Mean Method

• Scatter Plot

• Spearman’s Rank Correlation Coefficient

What is the formula for computing the correlation coefficient 'r' using Karl Pearson’s method?

• r = (Σxy) / (Nσxσy)

• r = Σ(XiYi) / NΣ(Xi)Σ(Yi)

• r = Σ(XiYi) / NΣ(XiYi)

• r = Σ(XiYi) / Σ(Xi^2)Σ(Yi^2)

What is the Spearman rank correlation coefficient when the sum of the squares of difference between the corresponding ranks is 96?

• 0.6

• 0.7

• 0.8

• 0.5