Question

The mean weight of 98 students as calculated from a frequency distribution is 50 kg.
It was later found that the frequency of the class 30-40 was wrongly taken as 8
instead of 10. Calculate the correct arithmetic mean.​

Answer 1

Answer:

Correct option is

49.70lbs.

Answer 2

Answer:

49.70 is the answer

Step-by-step explanation:

∑f

i

X

i

=Incorrect ∑f

i

X

i

−(8×35)+(10×35)

Note, the class-mark of class interval (30−40) is 35 and for the calculation of the mean, we consider class marks.

Correct ∑f

i

X

i

=4900−280+350

=4,970

Also, Correct ∑f

i

=98+2=100

∴ Correct Mean=

Correct∑f

i

Correct∑f

i

X

i

=

100

4970

X=49.70lbs.