Question

If the mean of 5 observation xx+2,x+4,x+6,x+8 is 11 then mean of first three observation

Answer 1

Here is your answer

Mean = Sum of 5 observations/Total numbers of observation

$11 = (x + x + 2 + x + 4 + x + 6 + x + 8) \div 5 \\ 11 \times 5 = 5x + 20 \\ 5x = 55 - 20 \\ 5x = 35 \\ x = 35 \div 5 \\ x = 7 \\ so \: first \: three \: observations \: are \\ 7 \\ 7 + 2 = 9 \\ 7 + 4 = 11$
7 ,9 ,11 are first three observations

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