Question

the mean of x, x+2, x+4, x+6, x+8 = 11. Find the mean of first three observations​

Answer 1

Step-by-step explanation:

$(x+ (x + 2) + (x + 4) + (x + 6) + (x + 8)) \div 5 = 11 \\ (5x + 20) \div 5 = 11 \\ 5x + 20= 11 \times 5 \\ 5x + 20 = 55 \\ 5x = 55 - 20 \\ 5x = 35 \\ x = 35 \div 5 \\ x = 7 \\ \\ mean \: of \: first \: three \: observations = (x + (x + 2) + (x + 4)) \div 3 \\ (3x + 6) \div 3 \\ (3 \times 7 + 6) \div 3 \\ (21 + 6) \div 3 \\ 27 \div 3 \\ = 9$

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