Question

Average of ten positive numbers is `barx`. If each number is increased by 10%, then `barx`

Options

• remains unchanged

• may decrease

• may increase

• is increased by 10%

Answer 1

is increased by 10%

Explanation:

`(x_1 + x_2 + .... + x_10)/10 = barx`

⇒ `x_1 + x_2 + ... + x_10 = 10  barx`

⇒ `110/100 x_1 + 110/100 x_2 + ... + 110/100 x_10 = 110/100 xx 10 barx`

⇒ `(110/100 x_1 + 110/100 x_2 + ... + 110/100 x_10)/10 = 11/10 barx`

⇒ Average is increased by 10%