Question

Q7.
Find the mean of the following data using short-cut-method: -
[3]
C.I
F
0-10
10
10-20
6
20-30
8.
30-40
12
40-50
5​

Answer 1

Answer:

Class interval Frequency (f

i

) x

i

=

2

lower limit + upper limit

f

i

x

i

0−10 7 5 35

10−20 8 15 120

20−30 12 25 300

30−40 13 35 455

40−50 10 45 450

Σf

i

=50 Σf

i

x

i

=1360

Mean =

Σf

i

Σf

i

x

i

=

50

1360

=27.2