# Hypothesis testing

Hypothesis testing

Hypothesis testing

HYPOTHESIS TEST QUESTION

The president of a company that manufactures air conditioners is considering switching his supplier of

condensers. SupplierA,the current producer of condensers for the manufacturer, prices its product 5%

higher than supplierBdoes. Because the president wants to maintain his company’s reputation for

quality, he wants to be sure that supplier B’s condensers last at least as long as supplier A’s condensers.

After a careful analysis, the president decided to retain supplierAif there is sufficient statistical

evidence that supplier A’s condensers last longer, on average than supplierB’scondensers. In an

experiment, 15 randomly-selected midsize cars were equipped using type-A condensers while another

15 randomly-selected midsize cars were equipped with type-B condensers. The number of kilometers

(in thousands) driven by each car before the condenser broke down is displayed in the table below.

SupplierA SupplierB

156 109

146 75

93 131

152 131

80 129

111 147

107 78

118 124

115 86

125 127

108 111

97 146

142 114

160136

10298

Carry out a hypothesistest, at 5% significance level, to determine whether the president should retain Supplier A.

‘Purchased materials costing \$250,000. ‘Used direct materials in produc
Purple holds assets valued at \$800,000 and liabilities at \$200,000. Brown Corporati

Please use attached excel spreadsheet for calculations. I will need this assignment back by Tuesday September 17, 2013 at 5 pm. I have completed the assignment but need to compare. 5-6 pages please

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Hypothesis Testing
In the banking industry, the return on equity ratio or percentage is used to evaluate the financial performance of a bank. Such information is extremely valuable to investors.
Calculate the return on equity (ROE) for a sample of 20 banks for the year before the Sarbanes-Oxley Act was enacted. For the same sample of banks, calculate the ROE for the year following the enactment of the Sarbanes-Oxley Act. Please use attached Excel spreadsheet.
After the enactment of the Sarbanes-Oxley Act, was the average bankâs ROE lower than it was before the act? If so, why do you think that was the case?
What is the null hypothesis for this hypothesis test?
What is the alternative hypothesis for this hypothesis test?
Choose at least three different significant levels to conduct the hypothesis test. Is it possible that a Type I error occurred with the hypothesis test? Why or why not?
Is it possible that a Type II error occurred? Why or why not?
5-6 pages

why do we use nonparametric tests? describe a psychological research situation or scenario that would use a non-parametric test. why would the non-parametric test be used?

9.64 An auditor reviewed 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above the reimbursed amount was \$275.66 with a standard deviation of \$78.11.

(a) At the 5 percent level of significance, does this sample prove a violation of the guideline that the average patient should pay no more than \$250 out-of-pocket?
State your hypotheses and decision rule.
(b) Is this a close decision?

Hypothesis Testing

1.Imagine that the population mean for the number of books read by 3rd graders is 47 with a population standard deviation of 8. The third grade class at Southview Elementary initiated a reading incentive program and based on a sample of 150 children, obtained a mean of 55 books.  The research question is whether the reading incentive program was successful in increasing the number of books read by 3rd graders. What test would be used? Calculate the test statistic.

2.In the example above:

What is the null hypothesis?
What is the alternate hypothesis?
Write these hypotheses in words and in symbols.
Is this a one- or two-tailed test? 3.
In the example above, use your calculation of the test statistic and the table in the back of your book to provide the best estimate for p (probability).
What does p represent?
What does alpha represent?
In order to support our alternate hypothesis, what should the relationship be between alpha and our p value?
4.In the example above, if alpha = .05, have we found support for our alternate hypothesis? Do we find support at alpha = .10? .01?
5.In testing the hypothesis, H0: ? ? 28.7 and Ha: ?