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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.
Solution
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
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