A baby dolphin is born into the ocean, which is a fairly cold environment. Water has a 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 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 (Dunkin et al. 2005). 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.