Question

Find the mean of the following data

Class

50-70

70-90

90-110

110-130

130-150

150-170

Frequency

10

18

7

6
5
4​

Answer 1

Answer:

10+18+7+6+5+4/6= 212/6= 35.333333

Answer 2

Step-by-step explanation:

Solution:-

Total number of frequencies = N = Σ fi = 50

Σ fiui = -10

Assumed mean = A= 100

Length of the class =h= 20

We know that mean =A+(Σ fiui /Σ fi )×h

Mean = 100+(-10/50)×20

=>100+(-1/5)×20

=>100 +(-20/5)

=>100+(-4)

=>100-4

=>96

Mean = 96

Used formula:-

mean =A+(Σ fiui /Σ fi )×h

Additional information:-

1. Mean is the central tendency is the result when the sum of the observations are divided by the number of observations .
2. It is also called as average .
3. There are three main methods for finding the mean ,they are : Direct method,Deviation method and step deviation method.