Module % Written Assignment

Module 5 Homework Assignment

1.  Find the critical value or values of χ²based on the given information.  H₁: σ > 26.1, n = 9, α = 0.01

2.  Test the claim that for the adult population of one town, the mean annual salary is given by
 μ = 30,000. Sample data are summarized as n = 17, = $22,298, and s = $14,200. Use a significance level of α = 0.05. State the null and alternative hypotheses.

-

3.  (Refer to Question 2) Find the test statistic.

4.  (Refer to Question 2) Find the critical value(s) and state and explain decision about null hypothesis.

5.  (Refer to Question 2) State the conclusion in non-technical terms.

6.  A manufacturer uses a new production method to produce steel rods. A random sample of 17 steel rods resulted in lengths with a standard deviation of 4.7 cm. At the 0.10 significance level, test the claim that the new production method has lengths with a standard deviation different from 3.5 cm, which was the standard deviation for the old method.  State the null and alternative hypotheses.

7.  (Refer to Question 6) Find the test statistic.

8. (Refer to Question 6) Find the critical value(s) and state and explain the decision about the null hypothesis.

9.  (Refer to Question 6) State conclusion in non-technical terms.

10. (Refer to Question 6) Calculate and show the confidence interval based on the significance level given above.  Are the results the same as in question 8 and 9?