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The answer to Hypotheses testing problems

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 15 recent mileages of Citrus cars was taken. The mean of these 15 mileages was 1517 miles per month, and the standard deviation was 203 miles per month.

Assume that the population of recent monthly mileages of Citrus cars is normally distributed. At the 0.05 level of significance, can it be concluded that the mean recent monthly mileage,m , of Citrus cars is less than 1550 miles per month?

Perform a one-tailed test. Then fill in the table below.

Carry your intermediate computations to at least three decimal places and round your answers as specified in the table.

The null hypothesis Ho __

The alternate hypothesis H1 __

They type of statistic (Z, t, chi square, F)__

The value of the test statistic: (Round to at least three deciamal places.)__

The critical value at the 0.05 level of significance: (Round to atleast three decimal places.)___

At the 0.05 level of significance, can it be concluded that the mean recent monthly mileage of Citrus cars is less than 1550 miles per month? (yes or no) __ .

Solution Preview

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Hypothesis
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 15 recent mileages of Citrus cars was ...

Solution Summary

The solution provides step-by-step method for the calculation of test statistic for t test. Formula for the calculation and Interpretations of the results are also included.

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