Question

The mean of four numbers is 32. If one more number is added to the collection, the new average of the five numbers becomes 31. Find the mean value of fifth observations.

Answer 1

Answer:27

Step-by-step explanation

Since the mean of four numbers is 32.

Therefore, the sum of all four numbers is (4×32)=128

Now,one more number is added then,

The mean becomes 31.

So,new sum of 5 numbers (5×31)=155

Therefore,the new number=155-128

=27

Answer 2

Answer:

27

Step-by-step explanation:

Mean=Sum of four numbers/4

32=Sum of four numbers/4

32x4=Sum of four numbers

128=Sum of four numbers

Let the fifth number be x

Then,

=Sum of four numbers+x/5

31=128+x/5

31x5=128+x

155=128+x

155-128=x

27=x

Hence,The fifth number is 27