17. Muscle strength declines as we grow old. Preliminary evidence suggests that part of this loss of muscle strength may be due to a deficiency of chemical X. Investigators plan a randomized trial to administer chemical X or identical placebo for 5 months to elderly subjects and then measure muscle strength. Previous studies report a mean grip strength in elderly persons of 20 kg with a SD of 5 kg. Assuming alpha (2-sided) = 0.05 and beta = 0.10. How many subjects would be required to demonstrate a 10% or greater difference between strength in the treated and placebo groups? What is the sample size?

Citrus Rental is a popular car rental agency that has a history of having too few cars available, so that its available cars are overdriven. The mean monthly mileage over the years for Citrus cars has been about  1550  miles per month. Recently, though, Citrus purchased thousands of new cars, and the company claims that the average mileage of its cars is now less than in the past. To test this, a random sample of  19  recent mileages of Citrus cars was taken. The mean of these  19  mileages was  1532  miles per month, and the standard deviation was  208  miles per month.   Assume that the population of recent monthly mileages of Citrus cars is normally distributed. At the  0.1  level of significance, can it be concluded that the mean recent monthly mileage,  μ , of Citrus cars is less than  1550  miles per month?   Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as…

If you have a research scenario in which the IV has three or more levels and is between subjects in nature with a quantitative DV, then you would use the One Way Between Subjects ANOVA. O True O False

A new screening test for Lyme disease is developed for use in the general population. The sensitivity and specificity of the new test are 60% and 70%, respectively. Five hundred people are screened at a clinic during the first year the new test is implemented. Assume the true prevalence of Lyme disease among clinic attendees is 10%. Calculate the predictive value of a positive test.