INTRODUCTION TO STATISTICS ECON1005 – Academic Year 2012/2013, Semester II
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ECON1005 – Introduction to Statistics COURSEWORK ASSIGNMENT #1
Graded Assignment 1
This assignment is to be prepared as a WORD document. It is based on your
understanding of the subject matter cover in Units 3, 4 and 5. The deadline for uploading
this Graded Assignment is 3:30pm EC Time on Monday March 11th, 2013. This
assignment has an allocation of 10 marks. You are required to attach their Individual
Plagiarism Statement. This is NOT a group assignment. It is expect that you will do your
own work. Presentation of another person's work will be severely penalized.
Submit your assignment to Turn-It-In AND also upload it in the appropriate drop box for
grading by your etutor. Note that your assignment should be entitled: Your First Name
Your Last Name ECON1005 Assignment #1. For example: Mary McDonald ECON1005
Assignment #1
Question 1 [20 marks]
A trucking company has been requested to quote a realistic turn-around time for a
contract to handle the distribution of a certain product to supermarkets around the
country. The company provided the following turn-around times for distributing similar
goods over a given twelve-month period.
Turn-around times in days Frequency
Less than 2 days 25
2 but less than 4 days 36
4 but less than 6 days 66
6 but less than 8 days 47
8 but less than 10 days 26
10 but less than 12 days 18
12 but less than 14 days 2
(a) What percentage of the time is the turn-around time less than 8 days? [2 marks]
(b) Which ONE of the following charts/diagrams would be most appropriate to display
the information given in the table above: bar chart, histogram, stem-and-leaf
diagram? State why the other charts/diagram are not suitable. [3 marks]
(c) Calculate the mean turn-around time. [3 marks]
continued overleaf…./
INTRODUCTION TO STATISTICS ECON1005 – Academic Year 2012/2013, Semester II
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(d) Calculate the standard deviation of the turn-around time. [5 marks]
(e) Calculate the median turn-around time. [5 marks]
(f) Advise the trucking company’s manager of the turn-around time to be quoted. Give
reasoning for your answer. [2 marks]
Question 2 [10 marks]
The monthly salaries of a simple random sample of 90 faculty members of
Brebnor University were recorded and processed using the MINITAB software.
See stem-and-leaf diagram below.
Stem-and-leaf of SALARY N = 90
Leaf Unit = 100
2 7 55
15 8 0012555555789
33 9 000011225556666788
(16) 10 0000002223555588
41 11 00001445556
30 12 00000358
22 13 02
20 14 005
17 15 9
16 16 00
14 17 056
11 18 0
10 19 0000
6 20
6 21 00
4 22 025
1 23 0
(a) Discuss the shape of the distribution. [2 marks]
(b) Compute the Mode, the Median and the Range of the sample data. [4 marks]
(c) Find the quartile deviation. [4 marks]
continued overleaf…./
INTRODUCTION TO STATISTICS ECON1005 – Academic Year 2012/2013, Semester II
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Question 3 [20 marks]
A group of randomly selected adults were asked if they are in favour of or against
cloning. The following table gives the responses:
In Favour Against No Opinion
Male 345 405 100
Female 200 530 120
(a) What is the most likely outcome? [2 marks]
(b) One person is selected at random from these adults. Find the probability that this
person is
i. In favour of cloning [2 marks]
ii. Female and in favour of cloning [2 marks]
iii. In favour of cloning given that the person is female [3 marks]
iv. A female given that she is in favour of cloning [3 marks]
v. Male or against cloning [4 marks]
(c) Are the events “male” and “in favour” mutually exclusive? Explain why or why
not. [2 marks]
(d) Are the events “female” and “no opinion” independent? Explain why or why not.
[2 marks]
Total 50 marks [Graded out of 10]