A consumer buying cooperative tested the effective heating area of 20 different electric space heaters with different wattages. Here are the results.

a. Compute the correlation between the wattage and heating area. Is there a direct or an indirect relationship?
b. Conduct a test of hypothesis to determine if it is reasonable that the coefficient is greater than zero. Use the .05 significance level.
c. Develop the regression equation for effective heating based on wattage.
d. Which heater looks like the “best buy” based on the size of theresidual?