Question

find md and sd for the followind data
score 4-5 ,6-7 ,8-9 ,10-11 ,12-13 ,14-15
frequency 4 ,10 ,20 ,15 ,8 ,3

Answer 1

Answer:

For calculating the Mean Deviation (M.D.) and Standard Deviation (S.D.) of the following above given data, let us first calculate certain information from the table in figure attached below:

                   

N = ∑f = 60  

¯x = ∑fXi / ∑f = 554 / 60 = 9.23

∑f( |Xi - ¯x|) = 121.84

∑f(Xi-¯x)² = 367.65

Now,  

M.D. = ∑f( |Xi - ¯x|) / N = 121.84 / 60 = 2.03

And,

S.D. = √[∑f(Xi-¯x)² / (N-1)] = √[ 367.65 / (60 - 1) = √6.2313 = 2.496

The figure attached below is the calculated values that are required for M.D. and S.D. in a tabular form: