One of the Founders of a Society for Skeptics Believes

Essay

One of the founders of a society for skeptics believes that people would benefit from a more questioning attitude about various claims that people make and he has developed a course to teach such skills. A standardized skepticism assessment has a μ = 90 and a σ = 20. A sample of n = 40 is obtained from students who have taken his course and their mean is M = 99.
a. Employ the four-step hypothesis testing procedure to determine the effectiveness of the course using a two-tailed z-test and an α = .01.
b. If a significant difference was found, determine the size of the effect.