Question

Question no-3:- Calculate Standard Deviation of the following data:
Time (in Days)
No. of elements
0-10
46
10-20
173
20-30
126
30-40
15
40-50
9​

Answer 1

Answer:

Marks Mid-values(X) f dxi=X−25/10 fdx

i

f dx

i

2

0−10 5 10 −2 −20 40

10−20 15 8 −1 −8 8

20−30 25 15 0 0 0

30−40 35 8 1 8 8

40−50 45 4 2 8 16

Total

45

−12 72

45

72

−

45×45

144

×10

=12.36