Relationships Between Variables

The response variable is:

• The variable we expect to explain or predict the value of the explanatory variable.

• Sometimes called the independent variable (IV)

• The variable we expect to change in response to the explanatory variable

• Also known as EV

We wish to investigate the relationship between the number seeds planted in a garden and the number of fruit grown. The explanatory variable (EV) is

• The number of fruit grown

• The amount of soil in the garden

• The number of hours spent watering the plants

• The number of seeds planted

We wish to investigate the relationship between the time spent shopping and the number of items bought. The response variable (RV) is

• The number of items bought

• The number of items at the shop

• The time spent shopping

• The time spent getting to the shops

Which of the following is true?

• We use the response variable to explain changes that might be observed in the explanatory variable.

• The explanatory variable is the variable we expect to be explained by the response variable

• The response variable is also known as the predictor variable

• The explanatory variable is used to explain or predict the value of the response variable

Studies have shown that the marks received by a student depend on the amount of hours spent studying. Which is the response variable (RV)?

• Hours spent studying

• Marks

• Both Marks and Hours spent studying

• None of the above

Estimate the value of r:

• -0.7
• 0.35
• 0.98
• 0.65

Estimate the value of r:

• 0.83
• 0.10
• -0.75
• 0.52

Estimate the value of r:

• 0.03
• -0.99
• 0.79
• -0.72

Estimate the value of r:

• 0.99
• 0.05
• -0.99
• 0.78

Estimate the value of r:

• -0.32
• -0.95
• 0.47
• -1