There is a grouped data distribution for which mean is to be found by step deviation method.
A = assumed mean
B = class interval
C = sum of products of ‘u’ and frequency for each class interval
D = Total number of observations
Which of the following statements is true regarding mean(m) for the grouped distribution ?
m= A + B(C/D)
The formula for mean by step deviation method is given below.
¯¯¯x = a + h( ∑fiui∑fi )
Here a = assumed mean = A
h = class interval = B
fi = frequency of ith class
ui = dih
di = xi – a
∑fiui = sum of products of ‘u’ and frequency for each class interval = C
D= total number of observation =∑fi
Hence m = A + B × CD