# how too find class marks ??explain with an example ?? wat is histogram , expalin with an example !? expain who to find scale with example !???

Class mark:

The mid-value of a class is called the class mark.

Consider a class interval 54.5 - 59.5, its class mark is find as:

Similarly class mark for any interval 110 - 120 is find as:

Histogram

They are used to show "continuous data", or the data that is distributed in small intervals within a certain range. For example, the histogram of number of students scoring the marks in a particular range is given below.

Here, the scored marks are distributed in the small intervals such as 0-10, 10-20, 20-30, 30-40 and 40-50 within the range of 10 marks.

Choosen Scale:

The scale is choosen as per the data given. For example, consider the data shown below

 Class interval Frequency 2.0−2.52.5−3.03.0−3.5 645

In this case we will choose the scale x-axis starting from 1.5 followed by every interval more than 0.5 the previous one.

Consider an another example as:

 Class interval Class mark Frequency Points 300−350350−400400−450450−500500-550 325375425475525 51017203 A (325, 5)B (375, 10)C (425, 17)D (475, 20)E (525, 3)

Here, the scale on x-axis is taken from 275 followed by every value more than 50 than the previous one.

Hope you get it!!

• 22
What are you looking for?