The rank-sum test is sometimes thought of as a test for population medians. Under the assumptions of equal spread and shape, the means of two populations will differ if and only if the medians differ; therefore tests for equality of population means are also tests for equality of population medians. This exercise illustrates that when these assumptions are seriously violated, the rank-sum test can give misleading results concerning the equality of population medians. Consider the following two samples:
a. Show that both samples have the same median.
b. Compute the P-value for a two-tailed rank-sum test. If small P-values provide evidence against the null hypothesis that the population medians are equal, would you conclude that the population medians are different?
c. Do the assumptions of the rank-sum test appear to be satisfied? Explain why or why not.
ANTHRO 2020 March 16, 2016 Early Woodlands (3000 – 1800 BP): Bridge-top mounds, small hamlets Sedentism- sedentary populations versus moving populations Small mounds located in the middle of a flood terrace Middle Woodland (1800 – 1300 BP) Hopewell Complex- name of a farmer who had a Hopewell mound on his farm (Morticai Hopewell) There are enormous mounds, but in this tradition you re seeing very large mound centers, with walls and enclosed. There are a number of them in the Scioto Valley. They seem to be places where people meet annually. Temporary leaders for each meeting Find pits of blades without any wear one them Animal bones, carvings that look like alligators, here in the Ohio Valley and Illinois Fort Ancient Actually Late Woodland, but they were originally thought to be from the Middle Woodland Mounds and pits throughout, pits were there to fill with water. Argues that there would be a village in the middle of it. Newark Earthworks Enormous site that stretches very far. The great Newark road, is this roadway that heads off towards Chillicothe and continues all the way there. Maize It really takes off in the Ohio Valley (1500-1200 years ago) Bow and Arrow Using sticks and refining the point for easier hunting for smaller or larger animals Late Woodland (1300 – 900 BP) Monks Mound Socially complex people in north America Cahokia Sports similar to lacrosse (found sticks and rocks shaped like