Chapter 15 - Statistics

Example 5. Calculate the arithmetic mean of the following frequency distribution:

Class Interval 0-30 30-60 60-90 90-120 120-150 150-180
Frequency 12 21 34 52 20 11

Solution:-

Class interval Frequency xi di = xi - 105 fi di
0-30 12 15 -90
30-60 21 45 -60
60-90 34 75 -30
90-120 52 105 = a 0 -0
120-150 20 135 30
150-180 11 165 60

Here, a = 105

Arithmetic mean =

 

Maths by Mr. M. P. Keshari
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Subjects Maths (Part-1) by Mr. M. P. Keshari
Chapter 9 Circle
Chapter 10 Tangents to a circle
Chapter 11 Geometrical Construction
Chapter 12 Troigonometry
Chapter 13 Height and Distance
Chapter 14 Mensuration
Chapter 15 Statistics
Chapter 16 Probability
Chapter 17 Co-ordinate Geometry