Question

The arithmetic mean of 98 items is 50 .Two Items 60 and 70 were left out at the time of calculation. what is the correct mean of all items?

Answer 1

as we have given mean and n

therefore we have to take out the sum of all the observations(x)

that is

x = mean × n

x= 30 ×100

x = 3000

now add the correct no. which were misread that is

add 23 and 11

and you will get

3034

now subtract the wrong no. that is

sub 32 and 12 from 3034

that will give you 2990

now it is your new sum of observations

therefore new mean will be

2990/100

=29.9

Answer 2

Answer:

Explanation:

Sum number items = n*mean

= (98+2)*50

= 5000

500+60+70 = 5130

correct sum = 5130

correct mean = 5130/100

= 51.3