Question

The mean of the first s observall
and last 8 observations is 20. If the mean
of all 15 observations is 19, then find the
8th observation.
26
(d) 16
(c) 17
(b) 18
(a) 19
​

Answer 1

Answer:

19

Step-by-step explanation:

a1+ a2 + ..a8 /8 = 18 ; a8 + ...a15 / 8 = 20 ..(1)

a1 + ...+ a15 / 15 = 19 ..(2)

From 1

a1 + a2 + ....+ A15 = ( 18 + 20 ) 8

( a1 + a2 +...a15) + a8 = 38× 8

From 2

19 × 5 + a8 = 38× 8

a8 = 19

Hope it helps you

Answer 2

Step-by-step explanation:

$◆ A_N_S_W_E_R ◆$

The correct option is

( a ) 19

Hope, it's help you.

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