Prepare a continuous grouped frequency distribution from the following data:
Mid-point Frequency
5 4
15 8
25 13
35 12
45 6
Also find the size of class intervals.

Solution:

Difference between two mid points is 15-5 i.e 10

It depicts that the width of class interval is 10

Consider a as the lower limit of the first class interval

So the upper limit = a + 10

Mid class of the first class interval = 5

We know that

Mid value = (Lower limit + Upper limit)/2

Substituting the values

5 = (a + a + 10)/2

By further calculation

5 = (2a + 10)/2

2a + 10 = 10

So we get

2a = 0

a = 0

First class interval is 0-10

The continuous grouped frequency distribution table is

Mid-point	Class Interval	Frequency
5	0-10	4
15	10-20	8
25	20-30	13
35	30-40	12
45	40-50	6

Therefore, the size of the class interval is 10.

✦ Try This: The scores (out of 100) obtained by 24 students in a mathematics test are as follows: 62, 40, 82, 56, 40, 79, 84, 42, 42, 10, 54, 34, 25, 78, 96, 84, 60, 52, 55, 20, 57, 50, 24, 56. Represent this data in the form of a frequency distribution.

☛ Also Check: NCERT Solutions for Class 9 Maths Chapter 14

---

NCERT Exemplar Class 9 Maths Exercise 14.3 Problem 4

Prepare a continuous grouped frequency distribution from the following data: Mid-point Frequency 5 4 15 8 25 13 35 12 45 6. Also find the size of class intervals.

Summary:

A continuous grouped frequency distribution is mentioned above. The size of the class intervals is 10

---

☛ Related Questions:

• Convert the given frequency distribution into a continuous grouped frequency distribution: Class Int . . . .
• The expenditure of a family on different heads in a month is given below: Head Food Education Clothi . . . .
• Expenditure on Education of a country during a five year period (2002-2006), in crores of rupees, is . . . .