The toco toucan, the largest member of the toucan family, possesses the largest beak relative to body size of all birds. This exaggerated feature has received various interpretations, such as being a refined adaptation for feeding. However, the large surface area may also be an important mechanism for radiating heat (and hence cooling the bird) as outdoor temperature increases. Here are data for beak heat loss, as a percent of total body heat loss, at various temperatures in degrees Celsius: Temperature (degrees Celsius)151617181920212223242526272 82930
Percent heat loss from beak3536382841435546395445586056626 7
a. The equation of the least-squares regression line for predicting beak heat loss, as a percent of total body heat loss from all sources, from temperature is: (Use decimal notation. Give your answer to four decimal places.)

b. Use the equation to predict (
±
0.01) beak heat loss, as a percent of total body heat loss from all sources, at a temperature of 25 degrees Celsius.

c. What percent (
±
0.01) of the variation in beak heat loss is explained by the straight-line relationship with temperature?

d. Find the correlation r (
±
0.001) between beak heat loss and temperature.