Basic Mathematics for College Students

Find the median of a set of values.

The mean is not always the best measure of central tendency. It can be effected by
very high or very low values. For example, suppose the weekly earnings of four
workers in a small company are $280, $300, $380, and $240, and the owner pays himself
$5,000 a week. At that company, the mean salary per week is

In the numerator, do the addition.

Do the division.

The owner could say, “Our employees earn an average of $1,240 per week.” Clearly,
the mean does not fairly represent the typical worker’s salary there.
A better measure of the company’s typical salary is the median:the salary in the
middle when all of them are arranged by size.

Smallest Largest

Two salaries Two salaries
The middle salary
The typical worker earns $300 per week, far less than the mean salary.

The Median

The medianof a set of values is the middle value. To find the median:

1. Arrange the values in increasing order.


2. If there is an odd number of values, the median is the middle value.


3. If there is an even number of values, the median is the mean (average) of
   the middle two values.

$240⎧⎪ (^) ⎪⎨$280⎪⎪⎩ $ (^300)  $380⎧⎪ (^) ⎪⎪⎨$5,000⎪⎪⎪⎩

$1,240



$6,200

5

There are 4 employees plus

the owner: 4  1 5.

Mean

$280$300$380$240$5,000

5

3

7.2 Mean, Median, and Mode 613

Course Grade Credits Weighted grade points

Speech C 2

Basic Mathematics A 4

French B 4

Business Law D 3

Study Skills A  1

Totals 14 39

4  1 →  4

1  3 → 3

3  4 → 12

4  4 → 16

2  2 → 4

To find the total number of credits, we add the values in that column (shown in
red), to get 14.

To find the GPA, we divide.

Do the division.

Round 2.785 to the nearest hundredth.

The student’s semester GPA is 2.79.

2.79

2.785

2.785

14 39.000

 28

11 0

 98

120

 112

80

 70

10

The total number of grade points

 The total number of credits



GPA

39

14