Question

The mean of six numbers : x - 5, X-1, X, X + 2, X + 4 and x + 12 is 15. Find the mean of first four numbers. ​

Answer 1

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chemical decomposition produced by passing an electric current through a liquid or solution containing ions.

Answer 2

Answer:

12

Step-by-step explanation:

The mean of six numbers are x – 5, x – 1, x, x + 2, x + 4 and x + 12 is 15

∴ Mean = ((x - 5) + (x – 1) + (x) + (x +2) + (x + 4) + (x + 12))/6

= (x – 5 + x – 1 + x + x + 2 + x + 4 + x + 12)/6

= (12 + 6x)/6 = 15

⇒ 12 + 6x = 90

⇒ 6x = 90 – 12

⇒ 6x = 78

⇒ x = 78/6 = 13

x = 13

∴ The six numbers are (13 – 5), (13 – 1), 13, (13 + 2), (13 + 4), (13 + 12)

i.e. 8, 12, 13, 15, 17, 25

Now, mean of first four numbers = (8 + 12 + 13 + 15)/4 = 48/4 = 12