Question

Directions: For each problem, use the specified approach to decide whether to reject the null hypothesis. In each case, be sure to: 1) Cite your evidence a. For the p-value approach, write the p-value and compare it to ? b. For the Critical Value approach, look up the CV(s) and either apply the appropriate mathematical rule or draw the rejection region diagram 2) State your conclusion about the null hypothesis (i.e. Reject ?o; Do not reject ?a) 3) State your conclusion about the alternative hypothesis (i.e. accept ?; ? is unsupported) 1. Consider a lower tail test at the ?0.10 significance level with test statistic ?1.19.
a) Use the Critical Value approach to decide whether to reject ?o.














b) Use the p-value approach to decide whether to reject ?o.
















Questions continue on the back
2. Consider a two-tailed test at the ?0.01 significance level with test statistic ?1.98. a) Use the Critical Value approach to decide whether to reject ?o.













b) Use the p-value approach to decide whether to reject ?o.







3. Consider an upper tail test at the ?0.05 significance level with test statistic ?2.54. a) Use the Critical Value approach to decide whether to reject ?o.













b) Use the p-value approach to decide whether to reject ?o.

Directions: Write out the solution for this hypothesis test: a) State the hypotheses (?a ??? ?o b) Calculate the appropriate test statistic, showing your work (at minimum, show the formula, the numbers filled into the formula, and the final answer). Round to two decimal places. c) Decide whether or not to reject ?. State your decision clearly. a. For this step, you must show both the critical value approach and the p-value approach d) Interpret the hypothesis test in terms of the original question. Be sure to reference the significance level in your interpretation. Answer the question: is there evidence that the customers at the new location are waiting too long on average?    

4. No customer wants to wait a long time in a checkout line. A retailer established a policy for mean time to check out at 240 seconds. After opening a new location, the retailer asked an analyst to see whether the new store was exceeding this standard (that is, whether customers were waiting too long to check out on average).

The analyst took a random sample of 30 customers at the new location and measured the time they had to wait to check out. In the sample of customers, the mean waiting time was 274 seconds. Drawing on past experience with checkout times, the analyst assumed a population standard deviation of 70 seconds.

Perform and interpret a hypothesis test to determine whether the population mean waiting time at the new location is longer than 240 seconds. Use an ?0.01 significance level.

Answer 1