15 Whales entangled in fishing gear. Marine Mammal Science

(April 2010) conducted a study of whales entangled in fishing gear. Data collected for a sample of 207 entanglements in the East Sea of Korea were used to model the length ( y )

of an entangled whale (in meters). Two independent variables used to predict whale length were water depth of the entanglement ( x 1 , in meters) and distance of the entanglement from land ( x 2 , in miles).

a. Give the equation of a first-order model for length ( y )

as a function of the two independent variables.

b. The researchers theorize that the length of an entangled whale will increase linearly as the water depth increases, for entanglements that are a fixed distance from land. Explain how to use the model, part

a, to test this theory.

c. The p -value for testing H0: b2 = 0 in the model, part a , was reported as .013. Interpret this result using a = .05 .