Arab Open University Tutor Marked Assignment (TMA) Academic Year 2015 - 2016 Semester: Fall 2015 - 2016 Branch: Program: Business Course Title: Analyzing Data Course Code: M248 Student Name: Student ID: Section Number: Tutor Name: Total Mark:100 A

Arab Open University
Tutor Marked Assignment (TMA)
Academic Year 2015 - 2016 Semester: Fall 2015 - 2016
Branch: Program: Business
Course Title: Analyzing Data Course Code: M248
Student Name:
Student ID:
Section Number: Tutor Name:


Total Mark:100
Awarded Mark:

Mark details
Allocated Marks Questions Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Total
Weight 14 20 12 12 12 12 12 6 100
Marks


Allocated Marks Criteria Presentation Referencing Word Count E-Library Total
Marks NA NA NA NA NA
Student’s Total Mark NA

Notes on plagiarism:
A. According to the Arab Open University By-laws, “the following acts represent cases of cheating and
Plagiarism:
 Verbatim copying of printed material and submitting them as part of TMAs without proper academic acknowledgement and documentation.
 Verbatim copying of material from the Internet, including tables and graphics.
 Copying other students’ notes or reports.
 Using paid or unpaid material prepared for the student by individuals or firms.
B. Penalties for plagiarism ranges from failure in the TMA to expulsion from the university.

Declaration: I hereby declare that the submitted TMA is my own work and I have not copied any other person’s work or plagiarized in any other form as specified above.
Student Signature

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Tutor Name: Tutor Signature: Date returned:

INSTRUCTIONS: The TMA consists of eight questions and it worth 20% of the total grade assigned to the course. It will be graded out of 100 marks divided amongst the seven questions. In your answers, please be sure to show all your calculations and to submit copies of your output when asked to use MS Excel or any other software/source.

Question 1: (14 points)

The quality rating and the meal price data were collected for a sample of 15 restaurants located in a small town. The data on restaurants’ quality rating and typical meal price are reported below:
Meal Price ($) Quality Rating Restaurant
11 Good 1
15 Very Good 2
16 Good 3
18 Very Good 4
14 Good 5
19 Excellent 6
20 Very Good 7
16 Very Good 8
20 Excellent 9
14 Good 10
21 Excellent 11
19 Very Good 12
24 Excellent 13
12 Good 14
14 Very Good 15


















a) What are the two variables under study? And what are their types?
b) Summarize the above data in a 3×3 table (Contingency table)

Meal Price ($)
Quality Rating [$10 – $15[ [$15 – $20[ [$20 – $24[ Totals
Good
Very Good
Excellent
Totals

c) Based on the table of part b), what chart could be used to display meal prices? Justify your answer.
d) Use MS Excel to construct the chart that displays meal prices in part b).
A proper chart must contain (title, labels for axes, frequencies, ….…)
e) What is the percentage of restaurants that are rated very good and above? Round your answer to two decimal places.
f) What is the percentage of restaurants offering meals with prices less than $15? Round your answer to two decimal places.

Question 2: (20 points)

A doctor’s office staff studied the waiting times for patients who arrive at the office with a request for emergency service. The following data with waiting times in minutes were collected over a one-month period.

8 7 9 14 15 10 9 9 13 6

a) Calculate the mean and the median number of waiting minutes for patients who arrive at the doctor’s office. What can you say about the skewness of the data set? Justify your answer.
b) Would any of the given numbers be considered an outlier? Justify your answer.
c) Determine the sample standard deviation.
d) Consider below the boxplot of the given data, comment on its skewness.


Question 3: (12 points)

A volunteer ambulance service handles 0 to 5 service calls on any day. The probability distribution for the number of service calls is as follows.

Number of Service calls: x 0 1 2 3 4 5
P(X=x) 0.1 0.15 0.3 0.2 0.15 0.1

a) What is the expected number of service calls?
b) What is the standard deviation in the number of service calls?
c) Determine the Cumulative Distribution Function?
d) What is the probability that only one service call was handled on a given day?
e) What is the probability that at least 3 service calls were handled on a given day?
Question 4: (12 points)

Is lack of sleep causing traffic fatalities? A study found that the average number of fatal crashes caused by drowsy drivers each year was 1550. Assume the annual number of fatal crashes per year is normally distributed with a standard deviation of 300.

a) What is the probability the number of fatal crashes will be between 1000 and 2000 for a year?
b) For a year to be in the upper 5% with respect to the number of fatal crashes, how many fatal crashes would have to occur?

Question 5: (12 points)

A survey by the society for Human Resource Management asked 400 job seekers why employees change jobs so frequently. The answer selected most (152 times) was “higher compensation elsewhere”. What is the 95% confidence interval of the population proportion of job seekers who change jobs because of higher compensation? (Round your answers to 2 d.p.). Interpret your results.

Question 6: (12 points)

A sample of 24 different payroll departments found that the employees worked an average of 310.3 days a year with a standard deviation of 23.8 days. What is the 90% confidence interval for the average days worked of all payroll departments? (Round your answers to 2 d.p.). Interpret your results.

Question 7: (12 points)

A sample of 200 coffee drinkers and 90 non-coffee drinkers were asked if they’ve had a good night sleep last night. 120 of the coffee drinkers and 72 non-coffee drinkers responded that they did. Construct a 99% confidence interval for the difference in the proportions of coffee drinkers and non-coffee drinkers who had restful nights. (Round your answers to 2 d.p.).

Non-coffee drinkers Coffee drinkers
90
200

72
120


Question 8: (6 points)

How much money does the average professional football fan spend on food at a single football game? That question was posed to 10 randomly selected football fans. The sampled results show that the sample mean and sample standard deviation were $70.00 and $17.50, respectively.

Use MS EXCEL (Interactive Sheets on moodle) or any other open source (online) to construct the 95% confidence interval estimate for the population mean.

• If you are using MS Excel, copy and paste your output to your TMA.
• If you are using an open source (online) use print screen and paste your output to your TMA.

Examples of open sources:

http://calculator.tutorvista.com/confidence-interval-calculator.html

http://www.danielsoper.com/statcalc3/calc.aspx?id=96