Question

If three arthmethic means are are inserted between -15 and 9,find the first of these arthmetic means.

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Answer 1

- 9

Explanation:

We require

- 15 , m₁, m₂, m₃, 9

The average of the end values gives m₂ , that is

m₂ =
`(-15+9)/(2)` =
`(-6)/(2)` = - 3

Similarly, the average of - 15 and m₂ gives m₁

m₁ =
`(-15-3)/(2)` =
`(-18)/(2)` = - 9

The first arithmetic mean m₁ = - 9