Statistics for Economics and Business 1 (ECON205)
Faculty of Economics and Management Science (FEMS)
Semester: First Semester
Level: 200
Year: 2019
Exercise one (25 marks)
An administrator wanted to study the utilization of long-distance telephone service by a
department. One variable of interest is the length, in minutes, of long-distance calls made for
one month. There were 38 calls that resulted in a connection. The length of calls, already
ordered from smallest to largest, are presented in the table below. Locate the quartile and
determine the 90
th
percentile.
Table; the length of long-distance phone calls in minutes
1.6 1.7 1.8 1.8 1.9 2.1 2.5 3.0 3.0 4.4
4.5 4.5 5.9 7.1 7.4 7.5 7.7 8.6 9.3 9.5
12.5 15.3 15.5 15.9 16.1 16.5 17.5 17.3 17.5 19.0
19.4 22.5 23.5 24.0 31.7 32.8 43.5 53.3
Exercise 2 (13 marks)
Indicate whether the following statements are true or false
A sample statistic is a numerical value used as a summary measure for a population
A population parameter is a numerical value used as a summary measure for a sample
A mean is a measure of central location computed by summing the data values and dividing
by the number of observations
A median is a measure of central location provided by the value in the middle when the data
are arranged in ascending order
A mode is a measure of variability, defined as the value that occurs with greatest frequency
A percentile is a value such that at least p percent of the observations are less than or equal
to this value and at least (100 – p) percent of the observations are greater than or equal to this
value. The 50
th
percentile is not the median.
Quartiles are the 25
th
, 50
th
and 75
th
percentiles, referred to as the first quartile, the second
quartile (median), and third quartile respectively. The quartiles can be used to divide a data
set into four parts, with each part containing approximately 25% of the data.
A range is a measure of location, defined to be the largest value minus the smallest value.
THE UNIVERSITY OF BAMENDA
FACULTY OF ECONOMICS AND MANAGEMENT SCIENCES
Semester Exam Course: Statistics for Econs and Business 1: ECON205
Credit Value:
Course Lecturers:
Time: Course Status: Date:
Venue: Instruction:
www.schoolfaqs.net
