Practice Exam: Intro Stats - Hypothesis Testing, Confidence Intervals, Normal Dist. - Prof, Exams of Statistics

Download Practice Exam: Intro Stats - Hypothesis Testing, Confidence Intervals, Normal Dist. - Prof and more Exams Statistics in PDF only on Docsity! STAT 269 { Introductory Statistics Practice Exam 2 1. A study of the e ect of nicotine withdrawal on time perception was conducted at Penn State in 2002. The conjecture was that the e ects of withdrawal would cause smokers who are trying to quit to overestimate the length of time they had to wait for something. The researchers had a random sample of 20 smokers go 24 hours without smoking, or using any nicotine replacement, and then had them estimate a time 45 second interval. The smokers averaged 59.30 seconds for their estimates, with a standard deviation of 9.84 seconds. Based on this data, can it be proven that withdrawal does result in an overestimation of waiting time? (use the appropriate test with a level of 0.05) 1) 2) 3) 4) 5) 6) 2. A study in 1999 looked at the potential for violent behavior in the workplace. 750 workers were surveyed, with 125 of them indicating that they were so angered by a coworker in the previous 12 months that he or she felt like hitting the person, though they restrained themselves. Assuming that this was a random sample of workers, nd a 95% con dence interval for the true proportion of workers that have been angry enough in the last 12 months that they wanted to hit a colleague. 1) 2) 3) 4) 5) 6)