FACULTY OF COMMERCE, MANAGEMENT AND LAW
Question 1
[80]
Selling prices (N$ 1 000s) for a sample of 25 two-bedroom house in a certain town are given in the
table below:
Selling price (N$)
Selling price (N$)
1
572
16
689
2
945
17
488
3
831
18
566
4
631
19
987
5
553
20
830
6
871
21
617
7
980
22
760
8
482
23
898
9
570
24
516
10
950
25
969
11
916
12
488
13
405
14
901
15
554
Required:
1.1 Calculate and interpret the following descriptive statistics measures:
(20) a)
Mean
b) Mode
c) Median
d) Third quartile
e) 60th percentile
f) Standard deviation
1.2 Construct a frequency distribution for the random variable Selling price. Use 5 classes. (10)
1.3. Construct a graphical representation for the cumulative percent frequency distribution for the
random variable Selling price. Approximate the percentage of houses with a selling price above N$
700 000.
(15)
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FACULTY OF COMMERCE, MANAGEMENT AND LAW
1.4 Use the frequency distribution constructed in 1.2 and calculate the following descriptive
statistics
measures:
(25) a)
Mean
b) Mode
c) Median
d) Third quartile
e) 60th percentile
f) Standard deviation
1.5 Compare your answers in 1.1 and 1.4. Explain why there is a difference.
(10) Question 2
[20]
Selling prices (N$ 1 000s) and Valuations (N$ 1 000s) of a random sample of ten two-bedroom
apartments sold during the last quarter of 2021 are shown in the table below:
Selling price (N$ 1000)
Valuation (N$ 1000)
1
572
488
2
945
988
3
831
766
4
631
587
5
553
430
6
871
617
7
980
760
8
482
498
9
570
516
10
950
969
Required:
a) Construct a scatter diagram for the data.
b) Calculate and interpret the correlation coefficient.
-----------------------------------END OF ASSIGNMENT 1----------------------------------
ABA 3691
ASSIGNMENT II 2022 ACADEMIC YEAR
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FACULTY OF COMMERCE, MANAGEMENT AND LAW
Question 1
[25]
In a survey conducted among a random sample of students the following observations were made
regarding their gender and learning environment preferences during the COVID-19 pandemic:
168 prefer online learning
202 prefer face to face learning
180 prefer blended learning
34 male students prefer online learning and 70 male students prefer blended learning
106 female students prefer face to face learning Required:
a) What is the probability that a female student is chosen?
b) What is the probability that a male student prefers face to face learning?
c) What is the probability that a student prefers online or blended learning?
d) If it’s known that the student is female, what is the probability that this student prefers
online learning.
e) Using a practical example, explain the difference between mutually exclusive events and
independent events.
Question 2
[25]
Suppose that the latest census indicates that for every 10 young people available to work only 4 are
employed. Suppose a random sample of 20 young graduates is selected.
Required:
a) What is the probability that they are all employed?
b) What is the probability that none of them are employed?
c) What is the probability that at least four are employed?
d) What is the probability that at most fifteen are employed?
e) What is the probability that the number of young graduates who are employed is greater
than ten but less than fifteen?
f) What is the expected number of graduates who are not employed?
g) What is the standard deviation for the number of graduates who are not employed?
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FACULTY OF COMMERCE, MANAGEMENT AND LAW
Question 3
[25]
Suppose that a mobile telecommunication company’s helpline receives five calls, on average, per
minute.
Required:
a) Discuss the difference between the Binomial probability distribution and the Poisson
probability distribution.
b) How many calls does the company expect to receive in a period of 30 minutes?
c) What is the probability that the company will receive at most four calls in a period of 4
minutes?
d) What is the probability that the company will receive at least three calls in a period of 5
minutes?
e) What is the probability that the company will receive between six and nine calls in a period
of 2 minutes?
Question 4
[25]
The amount of time devoted to preparing for a statistics examination by students is a normally
distributed random variable with a mean of 17 hours and a standard deviation of 5 hours.
Required:
a) What is the amount of time below which only 15% of all students spend studying?
b) What is the amount of time above which only one third of all students spend studying?
c) What is the probability that a student spends between 16 and 20 hours studying?
d) What is the probability that a student spends at least 15 hours studying?
e) What is the probability that a student spends at most 18 hours studying?
----------------------------------------------END OF ASSIGNMENT 2----------------------------------
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