Many animals, including hums, tend to avoid direct eye contact and even patterns that look like eyes. Some insects, including moths, have evolved eye-spot. Patterns on their wings to help ward off predators. Scaife (1976) reports a study examine how eye-spot patterns affect the behavior of birds. In the study, the birds were tested in a box with two chambers and were free to mover form one chamber to another. In one chamber, two large eye-spots were painted on one wall. The other chamber had plain walls. The researcher recorded the amount of time each bird spent in the plain chamber during a 60-minute session. Suppose the study produced a mean of M = 37 minutes in the plain chamber with SS = 228 for a sample of n = 9 birds. (Note: If the eye-spots have a no affect, then the birds should spend an average of U = 30 minutes in each chambers.) a. Is this sample sufficient influence on the birds' behavior? Use a two-tail method with a =.05. b. Compute the estimated Cohen's d to measure size of the treatment effect. c. Construct the 95 % confidence interval to estimate the mean among of time spent on the plain side for the population of birds.