Question

The mean of 5 numbers is 6.A sixth number is added to the 5 numbers and the new mean is 7 what is the sixth number?
A.12
B.13
C.18
D.37

Answer 1

Answer:

12

Step-by-step explanation:

Let the sum of the 5 number be x

$\frac{x}{5} = 6 \\ x = 30$

So, the Sum of the 5 numbers is 30.

Now let the 6 number added be y

So we need to add y to the already existing sum of the 5 number which is 30. Also since y has been added to the observations, now the total number of observations is 6 So according to the formula :

$\frac{30 + y}{6} = 7 \\ 30 + y = 42 \\ y = 42 - 30 \\ y = 12$