Question

If the arithmetic mean of x, x + 3, x + 6, x + 9, and x + 12 is 10, the x =

Options

• 1

• 2

• 6

• 4

Answer 1

The given observations are x, x + 3, x + 6, x + 9, and x + 12.

\[\therefore \sum_{}x = 5x + 30, n = 5,\]`overlineX = 10`

Now,

`overlineX =( sumx)/n `

`10 = (5x + 30)/5`

`50 = 5x +30`

`5x = 20`

`x = 4`

Hence, the correct option is (d).