# Find the Mean of Each of the Following Frequency Distributions Class Interval 0-6 6-12 12-18 - Mathematics

Find the mean of each of the following frequency distributions

 Class interval 0 - 6 6 - 12 12 - 18 18 - 24 24 - 30 Frequency 7 5 10 12 6

#### Solution

Let the assume mean A = 15

 Classinterval Mid-value(x1) d1 = x1 - 15 "u"_1=(x_1-15)/6 Frequency(f1) f1u1 0 - 6 3 -12 -2 7 -14 6 - 12 9 -6 -1 5 -5 12 - 18 15 0 0 10 0 18 - 24 21 6 1 12 12 24 - 30 27 12 2 6 12 N = 40 sumf_1"u"_1=5

We have

A = 15 h = 6

Mean =A+hxx(sumf_1"u"_1)/N

=15+6xx5/40

=15+30/40

= 15 + 0.75

= 15.75

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#### APPEARS IN

RD Sharma Class 10 Maths
Chapter 15 Statistics
Exercise 15.3 | Q 8 | Page 23