A grouped frequency distribution table with classes of equal sizes using 63-72 (72 included) as one of the class is constructed for the following data :
30, 32, 45, 54, 74, 78, 108, 112, 66, 76, 88,
40, 14, 20, 15, 35, 44, 66, 75, 84, 95, 96,
102, 110, 88, 74, 112, 14, 34, 44.
The number of classes in the distribution will be :
a. 9
b. 10
c. 11
d. 12

Solution:

Let us arrange the data given in groups like 13-22, 23-32 …. 103-112

Class width will be 9

Let us arrange it in tabular form

Therefore, the number of classes in the distribution will be 10.

✦ Try This: In the class intervals 5-10, 10-15 the number 10 is included in : a. 5-10, b. 10-15, c. all the intervals, d. None of the above

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

NCERT Exemplar Class 9 Maths Exercise 14.1 Problem 9

A grouped frequency distribution table with classes of equal sizes using 63-72 (72 included) as one of the class is constructed for the following data : 30, 32, 45, 54, 74, 78, 108, 112, 66, 76, 88, 40, 14, 20, 15, 35, 44, 66, 75, 84, 95, 96, 102, 110, 88, 74, 112, 14, 34, 44. The number of classes in the distribution will be : a. 9, b. 10, c. 11, d. 12

Summary:

A grouped frequency distribution table with classes of equal sizes using 63-72 (72 included) as one of the class is constructed for the following data : 30, 32, 45, 54, 74, 78, 108, 112, 66, 76, 88, 40, 14, 20, 15, 35, 44, 66, 75, 84, 95, 96, 102, 110, 88, 74, 112, 14, 34, 44. The number of classes in the distribution will be 10

☛ Related Questions:

• To draw a histogram to represent the following frequency distribution : Class Interval 5-10 10-15 15 . . . .
• The mean of five numbers is 30. If one number is excluded, their mean becomes 28. The excluded numbe . . . .
• If the mean of the observations : x, x + 3, x + 5, x + 7, x + 10 is 9, the mean of the last three ob . . . .