Question

The mean age of 15 teachers of a school was 32 years. One you teacher aged 28 years join the school. find the new mean age of 16 teachers of the school ? ​

Answer 1

Answer :-

Mean = Sum of all observations / Number of observation

According to the question -

• Number of teachers = 15
• Mean = 32

So,

Sum of all teachers = Number of teachers × Mean age

= 32 × 15

= 480

Sum of ages of all teachers = 480 years

Now, a new teacher is added whose age is 28.

So, now the sum of ages of all teachers

= 480 + 28

= 508

Also, now the number of observations = 16

Mean = 508 / 16

= 31.75

New mean = 31.75 years.