(a) Consider the data from Exercise IV.7. Suppose we want to compare the Vermilion River to the average of the other two rivers. Calculate the value of the contrast. L, to measure the difference between the mean number of species (per 0.1 hectare) along the Vermilion River and the mean number of species (per 0.1 hectare) along the other two rivers.
(b) Find the SE of the contrast L from part (a). (Don't make an interval or do a test.)