DMS/DAC/DIB/DBF Apr - Jun 2025

QTS0109 BUSINESS STATISTICS

CONTINUOUS ASSESSMENT 1

INDIVIDUAL ASSIGNMENT 100 marks (30%)

Read the instructions in your course documents, in your student portal, Course Outline, CA outline and Canvas portal carefully. You will be penalized with marks deduction if the instructions are not strictly followed. If you have queries, read the Canvas Help and then email queries via your student portal.

Students are to upload their assignment by the due date to through their student portal account. After the due date, students’ submissions will not be entertained.

Students should a keep a copy of assignment submitted. All workings must be shown. The submitted report must show evidence that this is students’ own work.

Write your FULL Name AND your student ID as in the register on the answer script.

Please be reminded that plagiarism and collusion is a serious offence, and all cases will be referred to the administration. Grades will be withheld if the submission is suspected for plagiarism or collusion till investigations are completed.

Due date: 25 Apr 2025 (Fri), 11.59 am

Penalty Marks for Late Submission of Assignment

Within 24 hours: 20% to be deducted from total marks

More than 24 hours: submission will be graded zero

CA Submission

CAs must be submitted online via student portal. Please read through instructions in your student portal, CA outline and your Canvas carefully before submitting. If you have further queries, please read the Canvas Help. If after you have read the Canvas Help, you need assistance on Canvas submission, please email to itsd_simge@sim.edu.sg or call 6248  9393.  For non-Canvas issues please email [email protected].Please email with your student portal accounts. Email from other addresses will not be entertained. If issues raised are covered, you will be directed to read through instructions first. Please take time read through before raising issues.

CONTINUOUS ASSESSMENT 1 [Total marks: 100 marks (30%)]

Answer ALL questions in Sections A and B

Submit an Excel answer file in Canvas:

(1)       Use Section A sheet in the Excel data template provided in Canvas to answer questions from Section A.

(2)       Use Section B sheet in the Excel data template provided in Canvas to answer questions from Section B.

(Save your Excel file using the prescribed format QTS0109yourname e.g. QTS0109johntan.xls)

Section A (50 marks)

(1)       For each variable listed below, state the variable type.

[Qualitative,  Quantitative (Discrete)  or Quantitative Continuous)]

Variable	Variable Type
Car brand
Time spent to revise for exam
Student ID number
Number of lessons take per week

(8 marks)

(2)       For each of the following variables, state the Level of Measurement (Nominal, Ordinal

or Ratio).

Variable	Level of Measurement
Number of bedrooms in one house
Hourly wage ($)
Associate ’ evaluation score on a scale of 1 to 5(1= Excellent to 5= Poor)
Different bachelor programmes (e.g. BSc of Data Science, BSc of Software Engineering, BSc of Accounting etc)
Nationality of the diploma students

(5 marks)

(3)       Del Transport Co has more than 300k rides per day. The company manager decides to take a sample of 500 passengers to assess their satisfaction with the services provided by the taxi company. The company has information about the passengers ’ age, gender, the phone number, the ride they booked and the fare they paid.

(a)       Describe how a simple random sample may be selected.

(b)       Describe how a stratified sample may be selected.

[Use your own words. Do not copy from any sources]        (8 marks)

(4)       State and briefly explain whether the statements below refer to descriptive or inferential statistics.

(a)       In Singapore, the median gross monthly starting salary for graduates in full- time permanent employment was S$4,313 in 2023.

(b)       In a survey of 300 students who are studying in NSU master programmes, 20% said that they are facing challenges about the study.

(c)       You survey 100 patients who go to International Family Clinic about whether they have diabetes. 15 of the 100 say they are suffering from diabetes. You infer that 15% of the patients who go to the clinic are having diabetes.   (9 marks)

(5)       A fitness center carried out a customer satisfaction survey in view of the center facility, cleanness, price and so on. The management team has put a bar code on the front desk for customer to scan. Many customers just simply sign the name of visiting and rush away without scanning the code. What is the main type of research bias that can occur here? Explain the bias stated.   (4 marks)

(6)       For each of the following situations stated below identify which refers to a population and which refers to a sample.

(a)       200 bottles ofthe vitamin is randomly selected for quality control and checking at Ministry of Food and Drug Safety.

(b)       The government has decided for each Singaporean child aged 12 and below, their family will receive $500 in LifeSG credits.   (4 marks)

(7)       The academic team would like to know the performance of the exam. The scores are shown in the stem and leaf diagram below. Total mark is 60.

key: 3|0 means 30

(a)       How many students were being selected by the academic team?        (2 marks)

(b)       What is the range of the students’ score?          (2 marks)

(c)       What is the mode student score?           (2 marks)

(d)       The mean score of past term exam is 38. The staff in the academic team claim that this time the mean score is higher. Is this claim correct? Justify your answer.           (3 marks)

(e)       The school has decided to give all the students whose score is below 30 a

supplementary exam. What percent of the students will take the supplementary exam?         (3 marks)

Section B (50 marks)

You are the Manager of Learning Vision tuition center which is a very popular tuition center that offers different courses such as PSLE, O-level and A-level preparation to different levels of the students. As the tuition center manager, you place great importance on students’ reviews and feedbacks. Therefore, you have decided to conduct an independent Student Satisfaction Survey to further improve the teaching quality and service level of the tuition center.

The questionnaire used to collect the data is shown below:

Survey of Students

Q1.       would you recommend this tuition center to your friends or classmates?     ①yes    ②NO

Q2.        How likely are you to continue the current programme for next semester?     ①Likely               @Unlikely

Q3.         How many subjects are you taking tuition for at our center (e.g. 2 subject)?  ______ subjects

Q4.        Tuition purpose:   ①passing the exam'module   ②   Getting A

Please select your level of agreement for the following statements [5=Strongly Agree (SA), 4= Agree (A), 3=Neutral(N), 2= Disagree (D), 1= Strongly Disagree(SD)]:

                                                                                                 SD         D            N           A           SA

Q5a	The price of the course is reasonable.	1	2	3	4	5
Q5b	The location of the center is very convenient.	1	2	3	4	5
Q5c	I am satisfied with the environment of the center.	1	2	3	4	5
Q5d	I am satisfied with the front desk or hotline service of the center.	1	2	3	4	5
Q5e	I am satisfied with the teaching of the center.	1	2	3	4	5
Q5f	In general, I am satisfied with studying in the center.	1	2	3	4	5

Using EXCEL, carry out relevant analyses to answer the following questions:

(8)       Create a histogram  for  variable  Q3 (number of subjects).  Label all axes clearly.   (5 marks)

(9)       Calculate  the  following  statistics  for  Q3  (number of subjects)  for  the  two  types of purposes (variable Q4). Tabulate your statistics as follows:

Tuition purpose	Mean	Median	Standard Deviation
Passing the exam/ module
Getting A

Discuss your results.          (10 marks)

(10)     You would like to look at the relationship between the marketing fee tuition center put

in per year and revenue (‘000) made yearly.  The following data were collected:

Advertising fee	1000	1300	1400	1500	1100	1300	1400	1100	1500	1600	1700
Revenue	210	270	340	350	250	260	360	200	370	390	400

(a)       Input above data in an excel worksheet.          (3 marks)

(b)       Construct a scatter diagram using Marketing fee on the horizontal axis and Revenue on the vertical axis. State the direction of relationship.         (4 marks)

(c)       Explain why “Marketing fee” is plotted on the horizontal axis.          (3 marks)

(11)     Given the following frequency distribution of final revenue (‘000) for a sample of 10 years.

Revenue			No of Quarters
200	up to	250	2
250	up to	300	4
300	up to	350	3
350	up to	400	1
Total			10

Calculate the grouped mean and grouped sample standard deviation. (Format finalanswers to 2 decimal places) (5 marks)

(12)     Create a contingency table with Q2 (Continue the current programme for next semester) as the row variable and Q1 (Recommend tuition center) as the column variable. Label clearly and comment on the results.      (6 marks)

(13)     Create a pie chart for the variable Q5e (Satisfied with the teaching of the center). Label your chart clearly.      (4 marks)

(14) Data preprocessing (maximum: 250 words)

Read through the core module “Data Analytics” before you attempt this question. Data preprocessing is a crucial step in data analysis. If the data itself contains typo, missing values and outliers etc, it can significantly impact the results of data analysis.

(a)       Please discuss the importance of data preprocessing.          (5 marks)

(b)       Please demonstrate two aspects of data preprocessing. [Hint: you can consider what data scientist do during data preprocessing and what methods they are using.]         (5 marks)