Which feature of geography was the most important in the development of early river valleycivilization?

Adolescents can display egocentrism when they become about changes in their lives.

The authors of the paper "fudging the numbers: distributing chocolate influences student evaluations of an undergraduate course"† carried out a study to see if events unrelated to an undergraduate course could affect student evaluations. students enrolled in statistics courses taught by the same instructor participated in the study. all students attended the same lectures and one of six discussion sections that met once a week. at the end of the course, the researchers chose three of the discussion sections to be the "chocolate group." students in these three sections were offered chocolate prior to having them fill out course evaluations. students in the other three sections were not offered chocolate. the researchers concluded that "overall, students offered chocolate gave more positive evaluations than students not offered chocolate." indicate whether the study is an observational study or an experiment. give a brief explanation for your choice.

Let the sample size of leg strengths be 7 and the sample mean and sample standard deviation be 945 watts and 48 watts, respectively. (a) is there evidence that leg strength exceeds 900 watts at significance level 0.05? find the p-value. there is , evidence that the leg strength exceeds 900 watts at ? -0.05. 0.001 < p-value 0.005 0.05 p-value < 0.10 0.10 p-value < 0.25 o 0.010 p-value 0.025 (b) compute the power of the test if the true strength is 915 watts. (c) what sample size would be required to detect a true mean of 915 watts if the power of the test should be at least 0.9? n= exact number, no tolerance