The frequency of a particular data value is the number of times the data value occurs.

For instance, on the off chance that four understudies have a score of 80 in arithmetic, and afterward the score of 80 is said to have a recurrence of 4. The recurrence of an information worth is frequently spoken to by f. 

A recurrence table is built by masterminding gathered information esteems in rising request of size with their relating frequencies.

Year 8 Interactive Maths – Second Edition

Frequency and Frequency Tables

The frequency of a particular data value is the number of times the data value occurs.

For example, if four students have a score of 80 in mathematics, and then the score of 80 is said to have a frequency of 4.  The frequency of a data value is often represented by f.

A frequency table is constructed by arranging collected data values in ascending order of magnitude with their corresponding frequencies.

Example 5

The marks awarded for an assignment set for a Year 8 class of 20 students were as follows:

     6     7 5     7 7 8     7 6 9 7

     4     10 6     8 8 9     5 6 4 8

Present this information in a frequency table.

Solution:

ToStage 1: 

Develop a table with three segments. The primary section shows what is being organized in ascending order(for example the imprints). The most reduced imprint is 4. Thus, start from 4 in the main segment as demonstrated as follows.  construct a frequency table, we proceed as follows:

https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/Image11649.gif

Stage 2: 

Experience the rundown of imprints. The principal mark in the rundown is 6, so put a count detriment for 6 in the subsequent segment. The second imprint in the rundown is 7, so put a count detriment for 7 in the subsequent segment. The third imprint in the rundown is 5, so put a count detriment for 5 in the third segment as demonstrated as follows.

https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/Image11650.gif

We proceed with this procedure until all imprints in the rundown are counted. 

Stage 3: 

Check the number of count marks for each imprint and compose it in the third segment. The completed recurrence table is as per the following:

https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/Image11651.gif

Stage 1: 

Develop a table with three segments. The primary section shows what is being organized in ascending order(for example the imprints). The most reduced imprint is 4. Thus, start from 4 in the main segment as demonstrated as follows. 

Stage 2: 

Experience the rundown of imprints. The principal mark in the rundown is 6, so put a count detriment for 6 in the subsequent segment. The second imprint in the rundown is 7, so put a count detriment for 7 in the subsequent segment. The third imprint in the rundown is 5, so put a count detriment for 5 in the third segment as demonstrated as follows. 

We proceed with this procedure until all imprints in the rundown are counted. 

Stage 3: 

Check the number of count marks for each imprint and compose it in the third segment. The completed recurrence table is as per the following: 

All in all: 

We utilize the accompanying strides to build a recurrence table: 

Stage 1: 

Develop a table with three segments. At that point in the principal segment, record the majority of the information esteems in ascending order of magnitude.

Stage 2: 

To finish the subsequent section, experience the rundown of information esteems and spot one count mark at the suitable spot in the second segment for each datum esteem. At the point when the fifth count is gone after an imprint, draw a flat line through the initial four-count checks as appeared for 7 in the above recurrence table. We proceed with this procedure until all information esteems in the rundown are counted. 

Stage 3: 

Tally the number of count marks for every datum esteem and compose it in the third section. 

Class Intervals (or Groups) 

At the point when the arrangement of information esteems is spread out, it is hard to set up a recurrence table for each datum esteem as there will be such a large number of lines in the table. So we bunch the information into class interims (or gatherings) to enable us to compose, decipher and break down the information. 

In a perfect world, we ought to have somewhere in the range of five and ten lines in a recurrence table. Remember this when choosing the size of the class interim (or gathering). 

Each gathering beginnings at a data value that is a multiple of that group. For instance, in the event that the size of the gathering is 5, at that point, the gatherings should begin at 5, 10, 15, 20 and so forth. In like manner, on the off chance that the size of the gathering is 10, at that point, the gatherings should begin at 10, 20, 30, 40 and so on. 

The recurrence of a gathering (or class interim) is the quantity of information esteems that fall in the range determined by that gathering (or class interim).

Example 6

The number of calls from motorists per day for roadside service was recorded for the month of December 2003.  The results were as follows:

https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/Image11652.gif

Set up a frequency table for this set of data values.

Solution: To construct a frequency table, we proceed as follows:

https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/Image11653.gif
https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/Image11654.gif

Stage 1: Construct a table with three segments, and afterward compose the information gatherings or class interims in the main section. The size of each gathering is 40. Thus, the gatherings will begin at 0, 40, 80, 120, 160 and 200 to incorporate the majority of the information. Note that in certainty we need 6 gatherings (1 more than we previously suspected). 

https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/Image11655.gif

Stage 2: Go through the rundown of information esteems. For the primary information esteem in the rundown, 28, place a count detriment for the gathering 0-39 in the subsequent section. For the subsequent information esteem in the rundown, 122, place a count detriment for the gathering 120-159 in the subsequent segment. For the third information esteem in the rundown, 217, place a count detriment for the gathering 200-239 in the subsequent segment. 

https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/freqh1.gif

We proceed with this procedure until the majority of the information esteems in the set are counted. 

Stage 3: Count the number of count marks for each gathering and compose it in the third section. The completed recurrence table is as per the following

https://www.mathsteacher.com.au/year8/ch17_stat/03_freq/Image11656.gif