• 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 intervalFrequency

2.0−2.5

2.5−3.0

3.0−3.5

6

4

5

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

300−350

350−400

400−450

450−500

500-550

325

375

425

475

525

5

10

17

20

3

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!!

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