Example of a histogram and frequency table

Median

Histogram

Frequency table

-Also known as the average

Formula: total sum of data / total no. of data

-Also known as the middle number

There are two ways we can get the median of a set of numbers. The two ways are applied respectively when there is an even set of no.s and when there is an odd set of no.s

When there is an even set of no.s

When there is an odd set of no.s

Mode

- Also known as modal <insert variable--amount/km/kg>. or the number that occurs most frequently

Example 1: (there is 1 mode)

1, 2, 3, 3

Most frequent no. = 3

Mode = 3

Example 2: (there are 2 modes)

1, 2, 2, 3, 3

Most frequent no.s = 2 and 3

Mode = 2 and 3 (this is called bi-modal distribution)

Example 3: (there is no mode :D)

1, 2, 3, 4

There is no most frequent no. as each no. appears one time only. Therefore, there is no mode.

- mode cannot be determined exactly, but we can identify the class which corresponds to the highest frequency as the modal class

Formula for finding the mean

Mean and mode of a grouped data

Mid-Value (x)

- basically the middle value (median) of each class interval

Table for finding out the mean of a grouped data

Workings for finding the mean in grouped data

Mean weight of students

= 845 ÷ 17

= 49.7 kg (correct to 3 s.f.)

Final answer must have units!

Note: label the axes and the title in pen, the only thing that is to be done in pencil is the drawing of the bars

- constructed to display the information given in a frequency table

- a vertical bar graph with no gaps in between the bars

- the area of each bar is proportional to the frequency it represents

Histograms

Macro concept

**Maths unit summary group G**

**Hui Juan**

**Ianni**

**Jemima**

**Florence**

**Nicole Fan**

Mean

image adapted from: www.glittergraphics.org

Models