Question

Find x if:
(a) 7, 15, 6, 10, 4, and x have a mean of 9
(b) 10, x, 15, 20, x,x, 17, 7, and 15 have a mean of 12.

Answer 1

Answer:

please mark me as brainlist

Step-by-step explanation:

then I can see the question

Answer 2

Answer:

$a) \: \: \: \: Mean = \frac{Sum}{No \: \: of \: \: Terms} \\ 9 = \frac{42 + x}{6} \\ 9 \times 6 = 42 + x \\ 54 = 42 + x \\ 54 - 42 = x \\ \boxed{\underline{ \underline{12}} = x} \\ \\ b) \: \: \: \: Mean = \frac{Sum}{No \: \: of \: \: Terms} \\ 12 = \frac{84 + 3x}{9} \\ 12 \times 9 = 84 + 3x \\ 108 = 84 + 3x \\ 108 - 84 = 3x \\ 24 = 3x \\ \frac{24}{3} = x \\ \boxed{\underline{ \underline{8}} = x}$