SOLUTION: Solve completely. Follow the procedure below: A. Setup the null and alternate hypothesis B. What is the level of significance “a” (alpha)? What test will you use and how ma

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Question 1175855: Solve completely. Follow the procedure below:
A. Setup the null and alternate hypothesis
B. What is the level of significance “a” (alpha)? What test will you use and how many tails is it?
C. Find the Critical Value given the level of significance and the number of tails (and the given n if it is a t-test). Draw a
bell curve.
D. Write the Decision Rule given the Critical Value. Note: A two-tailed test will have a positive and a negative Critical Value.
E. Solve for the test statistic (z or t-test). Compare with the Critical Value.
F. Conclusion: Reject or Do Not Reject? Explain in terms of the decision rule.
z-test

4. The police force has a mean physical fitness rating of 72 points (on a 100-point physical endurance rating scale) and a standard deviation of 9 points. The police chief selects a sample of 64 police officers. They score a mean physical fitness rating of 74. Did the physical endurance of the police force change at a .05 level of significance?

Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website!

Hi Police force: μ = 72pts and σ = 9 Sample: n = 64 and x̄ = 74pts Ho: μ = 72 Ha μ > 72 1)Level of significance is .05 2) One-tailed, critical value = invNorm(.95) = 1.6448 3) Sample > 30, population σ known: use z-test 4) z = 2/(9/8) = 1.7778 z > critical value Reject Ho. Evidence shows an increase in the physical endurance of the police force mean ratings this season. Wish You the Best in your Studies.