Feeding habits of fish. Refer to the Brain and Behavior Evolution (Apr. 2000) study of the feeding behavior of black-bream fish, presented in Exercise 2.162 (p. 124).

Recall that the zoologists recorded the number of aggressive strikes of two black-bream fish feeding at the bottom of an aquarium in the 10-minute period following the addition LO9 

of food. The table listing the weekly number of strikes and the age of the fish (in days) is reproduced below.

Week Number of Strikes Age of Fish (days)

1 85 120 2 63 136 3 34 150 4 39 155 5 58 162 6 35 169 7 57 178 8 12 184 9 15 190 Based on Shand, J., et al. “Variability in the location of the retinal ganglion cell area centralis is correlated with ontogenetic changes in feeding behavior in the Blackbream, Acanthopagrus ‘butcher’.” Brain and Behavior, Vol. 55, No. 4, Apr. 2000 (Figure H).

a. Write the equation of a straight-line model relating number of strikes (y) to age of fish (x).

b. Fit the model to the data by the method of least squares and give the least squares prediction equation.

c. Give a practical interpretation of the value of b n 0 if possible.

d. Give a practical interpretation of the value of b n 1 if possible.

e. Test H0: b1 = 0 versus Ha: b1 6 0, using a = .10.
Interpret the result.