Ecology: Hummingbirds Bill Alther is a zoologist who studies Anna’s hummingbird (Calypte anna)

(Reference: Hummingbirds by K. Long and W.

Alther). Suppose that in a remote part of the Grand Canyon, a random sample of six of these birds was caught, weighed, and released. The weights (in grams) were 3.7 2.9 3.8 4.2 4.8 3.1 The sample mean is x 5 3.75 grams. Let x be a random variable representing weights of Anna’s hummingbirds in this part of the Grand Canyon. We assume that x has a normal distribution and s 5 0.70 gram. It is known that for the population of all Anna’s hummingbirds, the mean weight is m 5 4.55 grams. Do the data indicate that the mean weight of these birds in this part of the Grand Canyon is less than 4.55 grams? Use a 5 0.01.

AppendixLO1