Question

step deviation method​

Answer 1

a+ (£fiui/£fi)*h
Your Answer.
-Shiit Happens.

Answer 2

HEY !!HERE IS YOUR ANSWER ..

Step Deviation Method (Mean)
Step Deviation : Sometimes, during the application of the short-cut method for finding the mean, the deviation d, are divisible by a common number ‘h’ .In this case the di = xi – A is reduced to a great extent as di becomes di / h. So the formula of mean by this is :

Where ui = ( xi – A) / h ; h = class width and N = Σ fi
Finding mean by using this formula is known as the Step Deviation Method.
Some solved examples
_____________________________________________________________
2) Find the mean of following frequency distribution:
Class interval
0 - 10
10 - 20
20 - 30
30 - 40
40 - 50
Number of workers
7
10
15
8
10

Solution :
Class intervals Mid values (xi) Frequency (fi) di = xi - 25 ui = (xi - 25) / 10 fi ui
0-10
5
7
-20
-2
-14
10-20
15
10
-10
-1
-10
20-30
25
15
0
0
0
30-40
35
8
10
1
8
40-50
45
10
20
2
20
N = Σ fi = 50 4

A = 25 , h = 10 , N = 50 and Σ fi ui = 4

⇒ Mean = 25 + 10 x ( 4 / 50)
⇒ Mean = 25 + 0.8
∴ Mean = 25.8

don't forget to mark as brainliest. .