STATISTICS – MEAN

CONTENT

1. Mean (listed and tabulated data values)
2. Median
3. Mode of a Given Set of Data

Determining the Mean of a Given Set of Data

The mean sometimes called the arithmetic mean is the most common average.

If there are n numbers in a set, then

Mean = \(\frac{\text{sum of numbers in a set}}{n}\)

When the set of data is tabulated, we use the formula: \(\frac{Ʃfx}{Ʃf}\)

Example 1:

In a class test, a student had the following marks:

\(13, 17, 18, 8, 10\). What is the average mark?

Solution:

Average (mean) \(= \frac{\text{sum of numbers in a set}}{n}\)

\(= \frac{13 + 17 + 18 + 8 + 10}{5} \)

\(= \frac{66}{5} \)

\(= 13.2\)

Example 2: A hockey team has played eight games and has a mean score of \(3.5\) goals per game. How many goals has the team scored?

Solution:

Mean score \(= \frac{\text{number of goals}}{\text{number of games}}\)

\(3.5 = \frac{\text{number of goals}}{8}\)

Multiply both sides by \(8\)

\(3.5 × 8 =\) total number of goals

\(28 =\) total number of goals

Median

Median simply refers to the middle item when the set of data is arranged in the right order.