Case

Azzahra is a book publisher, publishes and distributes educational and non-educational books and sell them to libraries and bookstores within Saudi Arabia and in the Arabian Gulf Region (AGR).

Azzahra employs a professional editorial team. All printing and binding activities are outsourced. The annual revenue total 250 millions Saudi Riyals which are disbursed as follows:

Cash expenditures are 150 million Saudi Riyals. Non-cash expenditures are 50 million Saudi Riyals. While revenues may be paid in different currencies, all processed out in the main center in Riyadh and using Saudi Riyal.

Requirement

Suppose you are a member of the professional editorial team and your task is to audit the revenue and accounts receivable. You probably would like to perform your audit in the following order:

1- Establish audit objectives

2- Determine the scope of the audit

3- Apply the Seven Habits of Highly Effective People (expected outcomes).

4- Understand the auditee (gather relevant information, analytical procedures, control

analysis, process flow, process risks)

5- Identify and assess risks

6- Identify key controls

7- Evaluate controls

8- Create test plan

9- Develop work program

10- Gather evidences

11- Evaluate evidences and reach conclusion

12- Develop observation and formulate recommendation.

A business analyst wants to know if a new website design compared to an old website design is showing increased page views per visit. Two different samples of customers are randomly sent to one of two different websites, offering the same products, but with different designs. Use data from "website" sheet in excel. Is there a difference in average page views between the new and old website design?

Which is the correct statistical test?

Compare two different public company stocks during the last two month, and determinate the risk and returns?

A biologist claims that a specific type of hamsters live for longer than, or equal to, 5 years on average. From 2000 hamsters that she has in her lab, she selects a random sample of 50 hamsters for testing and recorded that they lived for 4.9 years on average.

Based published papers in the field, she knows that the standard deviation of the lifespan of this type of hamsters is 1/3 years. Help the biologist to conduct a hypothesis test at the significance level of 0.05.

1: Write down the claim in mathematical notations.

2. State the null and alternative hypotheses

3: Choose and list the level of significance

4: Specify the sample size and sample statistic distribution

5. Is this a two-tail test or a one-tail test? Display the null distribution for yourself.

7: Calculate both the test statistic AND p-value

8: Clearly express your conclusion in words

Slot machines are the favorite game at casinos throughout the United States (Harrah’s Survey 2002: Profile of the American Gambler). A local casino wants to estimate the difference in the percent of women and me who prefer the slots with a 95% level of confidence. Random samples of 320 women and 250 men found that 256 women prefer slots and 165 men prefer slots.

1-

-Hypothesis test for one population mean (unknown population standard deviation)

2-Confidence interval estimate for one population mean (unknown population standard deviation)

3-Hypothesis test for population mean from paired differences

4-Confidence interval estimate for population mean from paired differences

5-Hypothesis test for difference in population means from two independent samples

6-Confidence interval estimate for difference in population means from two independent samples

7-Hypothesis test for one population proportion

8-Confidence interval estimate for one population proportion

9-Hypothesis test for difference between two population proportions

10-Confidence interval estimate for difference between two population proportions

The National Endowment for the Humanities sponsors summer institutes to improve the skills of high school language teachers. One institute hosted 20 French teachers for four weeks. At the beginning of the period, the teachers took the Modern Language Association's listening test of understanding of spoken French. After four weeks of immersion in French in and out of class, they took the listening test again. (The actual spoken French in the two tests was different, so that simply taking the first test should not improve the score on the second test.) The Director of the summer institute would like to estimate the change (and hopeful improvement) in the teachers' skills after participating in the class.

1-

-Hypothesis test for one population mean (unknown population standard deviation)

2-Confidence interval estimate for one population mean (unknown population standard deviation)

3-Hypothesis test for population mean from paired differences

4-Confidence interval estimate for population mean from paired differences

5-Hypothesis test for difference in population means from two independent samples

6-Confidence interval estimate for difference in population means from two independent samples

7-Hypothesis test for one population proportion

8-Confidence interval estimate for one population proportion

9-Hypothesis test for difference between two population proportions

10-Confidence interval estimate for difference between two population proportions

What might the presidency look like in 50 years. Will america needs to rethink the presidency.? Explain your answer in minimum two paragraphs (8 sentences each).

Below are the results of a comparison of serum glucose results for a series of samples analyzed at a Core Lab with the glucose results for the same serum samples analyzed in the Emergency Department (ED) Lab.

Specimen #                 Core Lab                     ED Lab

1                               130                              126

2                               206                              198

3                                 83                                78

4                               104                              100

5                               256                              250

6                                 57                                53

7                               476                              464

8                               579                              560

9                               217                              211

10                                35                                32

11                                 65                                60

12                                 92                                86

13                               261                              252

14                               319                              304

15                               179                              170

16                                 79                                75

What is the correlation coefficient for serum glucose results between the two labs?

What is the linear regression for glucose results from the ED Lab (y) versus glucose results from the Core Lab (x)?

What can you conclude about the performance of the ED Lab for glucose?

This problem is to be solved by hand.

The weight and systolic blood pressure of 12 randomly selected males in the age group 25-30 are shown in the table below.

Subject 1 2 3 4 5 6 7 8 9 10 11 12

Weight (lbs), x 165 167 180 165 212 175 190 212 200 149 158 169

Systolic BP, y 130 133 150 128 151 146 150 140 148 125 133 135

(e) Test for significance of regression coefficient using the two-sided t-test and a = 0.05.

(f) Construct an analysis of variance table and use it to perform the hypothesis test of part (e). Restate the null and alternative hypotheses and interpret your results.

(g) Perform a residual analysis on the data.

(h) Summarize your analysis of parts (a)-(g) in paragraph form to determine the appropriateness of the model.