1 . The males of stalk-eyed, flied have long eye stalks. The females sometimes use the length of these eye stalks to choose mates. Is the male's eye stalk length affected by the quality of its diet? An experiment was carried out in which two groups of male "stalkies" were reared on different foods. One group was fed corn (considered a high quality food), while the other was fed cotton wool (a food substantially lower quality). Each male was raised singly and so represents an independent sampling unit. The eye spans (the distance between the eyes) were recorded in millimeters.
a. What is the best test to use for comparing the means of the two groups? Why?
b. Carry out the test identified in part (a), using α = 0.01.
2. A baby dolphin is born into the ocean, which is a fairly cold environment. Water has high heat conductivity, so the thermal regulation of a newborn dolphin is quite important. It has been known for a long time that baby dolphins' blubber is different in composition and quantity from the blubber of the adults. Does this make the babies better protected from the cold compared to adults? One measure of the effectiveness of blubber is its' "conductance." This value was calculated on six newborn dolphins and eight adult dolphins. The newborn dolphins had an average conductance of 10.44, with a standard error of the mean equal to 0.69. The adult dolphins'' conductance averaged 8.44, with the standard error of this estimate equal to 1.03. All measures are given in watts per square meter per degree Celsius
a. Calculate the standard deviation of conductance for each group.
b. Test the null hypothesis that adults and newborns do not differ in the conductance of their blubber.
3. Weddell seals live in the Antarctic and feed on fish during long, deep dives in freezing water. The seals benefit from these feeding dives, but the food they gain comes at a metabolic cost. The dives are strenuous. A set of researchers wanted to know whether feeding per seal was also energetically expensive, over and above the exertion of a regular dive.
a. Estimate the mean change in oxygen consumption during feeding dives compared with nonfeeding dives.
b. What is the 99% confidence interval for the population mean change?
c. Test the hypothesis that feeding does not change the metabolic costs of a dive.
Attachment:- Berg_HW#6.compressed.pdf