Researchers are concerned that the mean clutch size (number of eggs per nest) of robin's eggs in a particular forest has decreased from the mean of 4.8 eggs measured ten years ago. They plan to send out teams to locate and count the number of eggs in fifty different nests, and then perform a hypothesis test to determine if their concerns are well-founded. What is the most appropriate test to perform in this situation?
(A) A one-tailed t-test on one population mean.
(B) A one-tailed t-test on the difference between two independent population means.
(C) A one-tailed t-test on the mean difference between ordered pairs.
(D) A one-tailed z-test on a population proportion.
(E) A chi-squared test on independence between two variables.
Answer: A