regression problem with 2 input variables, we construct a classification tree with 4 terminal nodes. This means（

A dairy farmer thinks that the average weight gain of his cows depends on two factors: the type of grain that they are fed and the type of grass that they are fed. The dairy farmer has four different types of grain from which to choose and three different types of grass from which to choose. He would like to determine if there is a particular combination of grain and grass that would lead to the greatest weight gain on average for his cows. He randomly selects three one-year-old cows and assigns them to each of the possible combinations of grain and grass. After one year he records the weight gain for each cow (in pounds) with the following results. Is there sufficient evidence to conclude that there is a significant difference in the average weight gains among the cows for the different types of grain?  Cow Weight Gain (Pounds)   Grass A Grass B Grass B Grain A 163163 287287 305305 267267 304304 325325 198198 348348 172172 Grain B 338338 291291 223223 286286 168168…

Researchers constructed two test sheets, each sheet including 20 photos of the faces of dog–owner pairs taken at a dog lovers' field festival. The 20 sets of dog–owner pairs on the two sheets were equivalent with respect to breed, diversity of appearance, and gender of owners. On the first sheet, the dogs were matched with their owners, while on the second sheet, the dogs and owners were deliberately mismatched. Three experiments were conducted, and in all experiments, subjects were asked to "choose the set of dog–owner pairs that resemble each other, Sheet 1 or Sheet 2," and were simply told the aim of the research was a "survey on dog–owner relationships." In the first experiment, the original sheets were shown to subjects; in the second experiment, just the "mouth region" of the owners was blacked out in all the pictures on both sheets; in the third experiment, just the "eye region" of the owners was blacked out. Subjects were assigned at random to the three experimental groups, and…

You have two groups of researchers getting data on a new drug for Alzheimer’s patients with working memory loss. Both researchers give the same memory task performed using the Wisconsin Card Sorting Task and count the number of correct answers from 15 patients each.The results of Researcher A are: 60, 62, 70, 55, 78, 53, 78, 53, 70, 66, 62, 79, 51, 65, 69The results of Researcher B are: 68, 75, 71, 65, 58, 74, 68, 72, 60, 59, 72, 65, 70, 72, 69Which set of scores has a lower SEM? You should be able to do this just by looking at the raw scores, but of course you can do the math if it helps you answer the question.