The line of best fit for these data has the equation y = 0.12x + 3.37, where x represents the total square
footage of the house, and y represents the selling price,
in thousands of dollars, for the house. Which choice
best describes the meaning of the number 0.12 in this
equation?

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?