Question

The mean of 99th items is 55.The value of 100th item is 99 more then the mean of the 100 items.The value of 100 items is?
1)149
2)155
3)145
4)151​

Answer 1

Answer:

5544

Explanation:

Mean = (Total value of observations)/(Number of observations)

Total= 99×55

=5445

N ow,

Let the mean of 100 items be y

According to the condition,

(99×55 + y)/100 = y

5445 + 99y = 100y

y=5445

So,

The value of 100th item is

=5445+99

=5544

So,

The the value of 100th item is 5544

Hope this helps !!!!!!!!!!!

Answer 2

Answer:1 option no.2-155

Explanation:mean of 99 items= 55

Mean= total number of the observations/no. of observations

55=total number of the observations/99

Total number of the observations=55×99=5445

Now,

let the mean of 100 items be x

As per the question,

value of 100th item= 99 more than the mean of 100 items= 99+x

Value of 100 items=5445+99+x

Now,

Finding the mean of 100 items

Mean= total no. of observations/no. of observations

x= 5445+99+x/100

100x=5445+99+x

100x-x=5445+99

99x=5544

x=5544/99

x=56

Therefore,

Value of 100th item= 99+x=99+56=155