SOLUTION: Solve completely: 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 t

Question 1175859: Solve completely:
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).
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-value). Compare with the Critical Value.
F. Conclusion: Reject or Do Not Reject? Explain in terms of the decision rule.

2.) The mean gross annual incomes of certified waiters are normally distributed with the mean of $20,000 and a standard deviation of $2,000. The restaurant association wishes to find out whether their waiters earn more or less than $20,000 annually. They did a survey of 49 welders and found a sample mean of $21,200. With the level of significance at 0.10, can the association conclude that the mean income has changed?

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


Hi
Population:   μ = $20,000 and   σ = $2000
Sample:  n = 49 and   x̄ = $21,200
Ho:   μ =  $20,000 
Ha    μ >  $20,000
1)Level of significance is .10
2) One-tailed, critical value = invNorm(.90) =  1.2825
3) Sample > 30, population σ known: use z-test
4) 
      z = 1200/(2000/7) = 4.2
    z > critical value 
Reject Ho.  
Evidence shows an increase in the mean income.

Wish You the Best in your Studies.

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