. You should round your z-scores to two decimal places when using a normal distribution table and...
Question:
Testing claims. To avoid loss of points, you must meet all 5 requirements listed below whenever you are asked to test a claim or conduct a hypothesis test.
State the null hypothesis, H0H0, and the alternate hypothesis, HaHa, indicating which is the claim.
Show the calculation of the test statistic.
Depending on the method you use, list either (a) the p-value or (b) find the critical value(s). Note: One tail tests have only one critical value, but two tail tests have two.
State decision whether to reject or "fail to reject" the null hypothesis, H0H0.
State your conclusion about the claim.
2. To compare the life time of a device manufactured by two different companies, an engineer measured the life of 35 of the devices from company 1 and 32 of the devices from company 2. For company 1 the mean life was x1=26.8 months. Assume the population standard deviation for company 1 is 7.9 months. For company 2 the mean life was x2=30.2 months. Assume the population standard deviation for company 2 is 8.3 months. At =0.05 can the engineer reject the claim that the mean life of the device is the same for the two manufacturers?
3. A researcher compared the costs of two cars with similar features made by two manufacturers. For company 1 the mean cost for 44 cars was x1=$37,950. Assume the population standard deviation for company 1 is $2520. For company 2 the mean cost for 37 cars was x2=$35,800. Assume the population standard deviation for company 2 is $2875. At =0.05 can the researcher support the claim that the difference between the mean costs for the cars is more than $1000 for the two manufacturers? (Note: Before you attempt this problem, please review the supplementary document posted in learning module 3 of your Blackboard course, "Testing Nonzero Differences in the Means".)
Accounting What the Numbers Mean
ISBN: 978-0073527062
9th Edition
Authors: David H. Marshall, Wayne W. McManus, Daniel F. Viele,