Stat 200Week 6 Homework Solution Correct Answers2. List 3 measures one can take to increase the power of an experiment. Explain why your measures result ingreater power.65.Previously, an organization reported that teenagers spent 4.5 hours perweek, on average, on the phone. Theorganization thinks that, currently, the mean is higher. Fifteen randomly chosen teenagers were asked how manyhours per week they spend on the phone. The sample mean was 4.75 hours with a sample standard deviation of2.0. Conduct a hypothesis test. The null and alternative hypotheses are:a.Ho: =4.5,Ha: >4.5b.Ho:μ≥4.5,Ha:μ<4.5c.Ho:μ=4.75,Ha:μ>4.75d.Ho:μ=4.5,Ha:μ>4.577.An article in theSan Jose Mercury Newsstated that students in the California stateuniversity system take 4.5years, on average, to finish their undergraduate degrees. Suppose you believe that the mean time is longer. Youconduct a survey of 49 students and obtain a sample mean of 5.1 with a sample standard deviation of 1.2. Do thedata support your claim at the 1% level?83.According to an article inNewsweek, the natural ratio of girls to boys is 100:105. In China, the birth ratio is100: 114 (46.7% girls). Suppose you don’t believe the reported figures of the percent of girls born in China. Youconduct a study. In this study, you count the number of girls and boys born in 150 randomly chosen recent births.There are 60 girls and 90 boys born of the 150. Based on your study, do you believe that the percent of girls bornin China is 46.7?Preview Mode
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