Question

QUESTION 1 [13 MARKS]

Write down only the letter corresponding to your choice next to the question number.

1.1. A random variable that can assume only a finite number of values is referred to as a

a) Infinite sequence

b) Finite sequence

c) Discrete random variable

d) Discrete probability function

e) All of the above

1.2 Which one of the following statements is incorrect?

a) A data set provides information about people, objects or other entities.

b) If the possible measurements of the values of a variable are numbers, then the variable is quantitative.

c) Whether your group has lung cancer or does not represents a qualitative variable.

d) A questionnaire containing questions about their sex and occupation is an ordinal variable.

e) The number of cigarettes smoked per day is a discrete variable.

1.3 A sample of a population is:

a) An experiment in the population

b) A subset of the population

c) A variable in the population

d) An outcome of the population

e) None of the above

1.4 Consider the frequency distribution of an exam given below.

Class Frequency Cumulative Frequency

50 ≤ x < 60      2

60 ≤ x < 70 5

70 ≤ x < 80 - 21

80 ≤ x < 90 17

90 ≤ x < 100 12 50

Which one of the following statements is incorrect?

a) The total number is 50.

b) The frequency of the class 70 ≤ x < 80 is zero.

c) The cumulative frequency of the class 80 ≤ x < 90 is 38.

d) The relative frequency of the class 50 ≤ x < 60 is 0.04.

e) Most of exam is represented by the class 80 ≤ x < 90.

1.5 Weight is a variable

a) Continuous

b) Discrete

c) Nominal

d) Ordinal

e) Secondary

1.6 The Statistics Department randomly selected 15 students and recorded their marks (in percentage) during the last examination. The data of the 15 students are as follows: 50 72 63 60 80 79 41 48 23 72 96 34 43 55 51 Which of the following statements is incorrect?

a) The range is 73

b) The median is 55

c) The mean is 57.8

d) Five of the 15 students failed the examination, that is, they obtained less than 50%

e) Three of the 15 students obtained more than 75% in exam.

1.7 Primary data is data collected for:

a) Primary school children

b) The purposes of a research being done

c) Ministry of home affairs and for safety reasons

d) Storage so that it can be used after 10 years

e) None of the above

1.8 Researchers do sampling because of all of the following reasons except

a) Reduce cost

b) Can be done in a shorter time frame

c) Sampling is interesting

d) Easy to manage due to manageable logistics requirements

e) There is many people involved

1.9 Which one of the following statements is not true about the mean?

a) It is the best measure of central tendency when data is not skewed.

b) In a symmetric distribution, the mean, the median and the mode are all equal.

c) It is not affected by extreme values or outliers.

d) It utilizes all values in its calculation.

e) The value of the mean times the number of observations equals the sum of all observations

1.10 The following information is collected from an application form for a car-loan to a certain bank.

(1)Marital status

(2) Total of monthly expenditures in Namibian dollars

(3) Number of jobs in the past ten years

(4) Gender of the applicant

(5) Erf number of the applicant

Which of the above variables are quantitative?

a) 1 and 2

b) 2 and 3

c) 3 and 4

d) 1, 2 and 5

e) 2 and 5

1.11. Which of the following is not a measure of central tendency in a statistical distribution?

a) Mean

b) Median

c) Mode

d) Standard deviation

e) All of the above are measures of central tendency

1.12. Which of the following calculations or measures is from a sample?

a) Statistics

b) Parameters

c) Populations

d) Simple random sampling

e) None of the above

1.13. A measure of the average value of a random variable is called an

a) Variance

b) Standard deviation

c) Expected value

d) Coefficient of variation

e) None of the alternative answers is correct.

Answer 1