What is Frequency and Cumulative frequency with Example

What is frequency?

Frequency is the number of occurrences of a repeating event given per unit of time. For example: if a newborn baby's heart beats at a frequency of 60 times a minute, its period, T, — the time interval between beats is a second (60 seconds divided by 60 beats). Frequency is a crucial parameter utilized in statistics, science and engineering to specify the speed of oscillatory and vibratory phenomena, like audio signals (sound), vibrations, waves, radio, and light.

Cumulative frequency

Cumulative means "how much so far".

Think of the word "accumulate" which suggests to collect together.

To have cumulative totals, just add up the values as you proceed.

Example: Ravi has earned this much in the last 6 months:

Month	Earned
June	1200
July	500
August	1100
September	1000
October	5000
November	2000

To work out the cumulative frequency, just add up as you go.
The first line is easy, the total earned so far is the same as Ravi earned that month:

Month	Earned	Cumulative
June	1200	1200

But for July, the total earned so far is 1200 + 500 = 1700 :

Month	Earned	Cumulative
June	1200	1200
July	500	1700

And for August we continue to add up: 1700 + 110 = 2800

Month	Earned	Cumulative
June	1200	1200
July	500	1700
August	1100	2800

Do you see how we add the previous month's cumulative total to the present month's earnings?
Here is the calculation for the rest:

• September is 2800 + 1000 = 3800
• October is 3800 + 500 = 4300
• November is 4300 + 200 = 4500

And this is the result

Month	Earned	Cumulative
June	1200	1200
July	500	1700
August	1100	2800
September	1000	3800
October	500	4300
November	200	4500

The last cumulative total should match the entire of all earnings:

4500 is the last cumulative total ...
... it is also the entire of all earnings:

1200+500+1100+1000+500+200 = 4500

So we got it right.