1819 C2X §2.4

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Which exercises/theory should we discuss on the board?

Mean, Mode and Median

The Mean, Mode and Median are ways to describe numerical data.

Mode

The mode is the value with the highest frequency.

Grades from class 2R: 5, 6, 10, 8, 6, 7, 9, 5, 8, 7, 6.

Mode

The mode is the value with the highest frequency.

Grades from class 2R: 5, 6, 10, 8, 6, 7, 9, 5, 8, 7, 6.

Mode

The mode is the value with the highest frequency.

Grades from class 2R: 5, 6, 10, 8, 6, 7, 9, 5, 8, 7, 6.

The mode is the grade 6 (with a frequency of 3)

Mode

The mode is the value with the highest frequency.

If there is no single value with the highest frequency, there is no mode.

Both the grade 6 and 8 have the highest

frequency (4), therefore there is no mode.

Median

The median is the middle value, when the values are sorted from smallest to largest.

Grades from class 2R: 5, 6, 10, 8, 6, 7, 9, 5, 8, 7, 6.

Median

The median is the middle value, when the values are sorted from smallest to largest.

Grades from class 2R: 5, 6, 10, 8, 6, 7, 9, 5, 8, 7, 6.

Sorted small-large: 5, 5, 6, 6, 6, 7, 7, 8, 8, 9, 10

Median

The median is the middle value, when the values are sorted from smallest to largest.

Grades from class 2R: 5, 6, 10, 8, 6, 7, 9, 5, 8, 7, 6.

Sorted small-large: 5, 5, 6, 6, 6, 7, 7, 8, 8, 9, 10

The median is the grade 7.

Median

If the number of values is even, the median is the average of the two middle numbers.

5, 6, 6, 7, 8, 9

Median = (6 + 7)/2 = 6.5

Mean

The mean is the average of all values. You can calculate the mean by adding up all values and dividing the result by the number of values.

Grades from class 2R: 5, 6, 10, 8, 6, 7, 9, 5, 8, 7, 6.

The mean is the grade (5 + 6 + .... + 6)/11 = 77/11 = 7.

Mean

If you have a frequency table, you can calculate the mean by first multiplying all values with their frequency, adding up the results and dividing that result by the total of the frequencies.

The mean is the grade 77/11 = 7

Homework Monday 17-9

• Make the exercises from §2.4 from your chosen path:

- Support: 20, S21, 22, 23, S24, 25

- Standard: 20, 21, 22, 23, 24, 25

- Challenge: 20, 21, 23, 25, C5, C6

• Correct with a red pen
• Bring your workbook