Referring to Exercise 8.19, regard the sample of 15 alert times (which has standard deviation 1.026) as a preliminary sample. Determine the sample size needed to make us 95 percent confident that x-bar, the sample mean alert time, is within a margin of error of .3 second of μ, the population mean alert time using the new display panel.
Answer to relevant Questionsa. What does a population proportion tell us about the population? b. Explain the difference between p and p̂. c. What is meant when a public opinion poll’s margin of error is 3 percent? Suppose that 60 percent of 1,000 randomly selected U.S. adults say that they take part in some form of daily activity to keep physically fit. Based on this finding, find a 95 percent confidence interval for the proportion of ...Referring to Exercise 8.44, determine the sample size needed in order to be 99 percent confident that p̂, the sample proportion of ColorSmart-5000 television sets that last at least five years without a single repair, is ...In an article in the Journal of Retailing, J. G. Blodgett, D. H. Granbois, and R. G. Walters investigated negative word-of-mouth consumer behavior. In a random sample of 201 consumers, 150 reported that they engaged in ...Suppose that we wish to test H0: μ = 20 versus Ha: μ < 20, where the population standard deviation is known to equal 7. Also, suppose that a sample of 49 measurements randomly selected from the population has a mean equal ...
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