Identify the explanatory variable and the response variable.

A researcher investigates the relationship between house size (measured in square metres) and residential energy consumption (measured in kilowatt-hours per month). Which statement correctly identifies the variables in this investigation?

A researcher investigates the relationship between the amount of time spent exercising per week (in hours) and a student's resting heart rate (in beats per minute). The researcher collects data from 45 high school students over one semester. (a) State the explanatory variable. (1 mark) (b) State the response variable. (1 mark) (c) Explain why the variable stated in part (a) is the explanatory variable. (1 mark)

A health researcher collects data from 12 adults to investigate whether there is a relationship between weekly exercise duration and resting heart rate. The data are shown in the table below. (a) Identify the explanatory variable. (1 mark) (b) Identify the response variable. (1 mark) (c) Calculate the mean weekly exercise duration for the 12 adults. (1 mark) (d) Calculate the mean resting heart rate for the 12 adults. (1 mark)

A marine biologist is investigating the relationship between water temperature and the feeding rate of reef fish at different coastal sites. (a) Identify which variable is the explanatory variable. (1 mark) (b) Identify which variable is the response variable. (1 mark) (c) Use the data to calculate the mean water temperature, correct to 1 decimal place. (1 mark) (d) Determine the range of feeding rates observed across all sites. (1 mark)

A researcher investigates the relationship between the number of hours of sleep a person gets per night and their performance score on a cognitive test the following morning. Which statement correctly identifies the explanatory and response variables?