This is number 8. the second person got number 9
Variance = summation of (x - mean)^2 all divided by the number of dataset.
mean = (17 + 5 + 11 + 1 + 11)/5 = 9
Variance = [(17 - 9)^2 + (5 - 9)^2 + (11 - 9)^2 + (1 - 9)^2 + (11 - 9)^2]/5 = (8^2 + (-4)^2 + 2^2 + (-8)^2 + 2^2}/5 = (64 + 16 + 4 + 64 + 4)/5 = 152/5 = 30.4
Simplifying
12x + 10 + 3 + 8x = 0
Reorder the terms:
10 + 3 + 12x + 8x = 0
Combine like terms: 10 + 3 = 13
13 + 12x + 8x = 0
Combine like terms: 12x + 8x = 20x
13 + 20x = 0
Solving
13 + 20x = 0
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-13' to each side of the equation.
13 + -13 + 20x = 0 + -13
Combine like terms: 13 + -13 = 0
0 + 20x = 0 + -13
20x = 0 + -13
Combine like terms: 0 + -13 = -13
20x = -13
Divide each side by '20'.
x = -0.65
Simplifying
x = -0.65
