Graphing

Post date: Jun 16, 2010 5:42:35 PM

Mean, Median, Mode

Mean:

-- Also known as the average. The mean is found by adding up all of the given data and

dividing by the number of data entries.

Example:

- the grade 10 math class recently had a mathematics test and the grades were as

follows:

78

66

82 464 / 6 = 77.3

89

75 Hence, 77.3 is the mean average of the class.

+ 74

464

Median:

-- The median is the middle number. First you arrange the numbers in order from lowest

to highest, then you find the middle number by crossing off the numbers until you reach the

middle.

Example:

- use the above data to find the median:

66 74 75 78 82 89\

- as you can see we have two numbers, there is no middle number. What do we do?

It is simple; we take the two middle numbers and find the average, ( or mean ).

75 + 78 = 153

153 / 2 = 76.5

Hence, the middle number is 76.5.

Mode:

-- this is the number that occurs most often.

Example:

- find the mode of the following data:

78 56 68 92 84 76 74 56 68 66 78 72 66

65 53 61 62 78 84 61 90 87 77 62 88 81

The mode is 78.