Question

The mean monthly income of 10 persons is Rs 8,670. If a new member with a monthly income of Rs 9, 000 joins the group, find the new monthly income. 

Answer 1

Mean monthly salary of 10 people= Rs 8,670 

n=10 

`barx = (x_1 + x_2 + x_3 + .... + x_n)/n`

Rs.8 670 = `(Σx_n)/10`

⇒ `Σx_n` = Rs.86, 700 

Salary of new person = Rs 9000 

`Σx_n = "Rs".(86,700 + 9, 000)` 

`Σx_n = "Rs".95,700`

n= 11 

`barx = (x_1 + x_2 + x_3 + .... + x_n)/n`

⇒ `barx = ("Rs".95,700)/11`

⇒ `barx` =  Rs.8, 700 
The new mean monthly inoome = Rs 8, 700