Consider the following random variables:
Jessie’s weight, Ayanda’s monthly salary, Number of items Carey purchased in a week.
The data types, respectively, are:
A. Continuous, Discrete, Discrete.
B. Discrete, Continuous, Discrete.
C. Continuous, Continuous, Discrete.
D. Continuous, Continuous, Continuous.
Questions 2 – 8 refer to the (incomplete) grouped frequency distribution below which depicts the test scores (%)
of 40 students.
Test scores (%) Number of students Midpoint
(m)
fm fm2
0 < 20 5 10
20 < 40 9 30
40 < 60 16 50
60 < 80 7 70
80 < 100 3 90
S 40 - A B
QUESTION 2 (4 Marks)
The values of A and B, respectively, are:
A. 1808 and 107 200
B. 1880 and 107 200
C. 1880 and 172 000
D. 1880 and 3534 400
QUESTION 3 (4 Marks)
The estimated mean score (%) is:
A. 50
B. 45
C. 42
D. 47
QUESTION 4 (4 Marks)
The median score (%) is:
A. 47.5
B. 45.5
C. 43.5
D. 49.5
QUESTION 5 (4 Marks)
The modal score (%) is:
A. 48.75
B. 47.25
C. 45.75
D. 50.5
QUESTION 6 (4 Marks)
The variance is closest to:
A. 407.6
B. 341.0
C. 576.8
D. 483.1
QUESTION 7 (4 Marks)
The coefficient of variation is closest to:
A. 42.5%
B. 38.9%
C. 46.8%
D. 49.0%
QUESTION 8 (4 Marks)
The 80th percentile is closest to:
A. 69.5%
B. 65.7%
C. 71.8%
D. 62.9%
QUESTION 9 (4 Marks)
Which one of the following is NOT a binomial experiment?
A. The tossing of a coin.
B. The response to the question “What is your favourite colour?”
C. Rolling a dice to see if a “six” is the result.
D. The recurrence of a hernia after surgery.