Expected Mean, E(X), is obtained by multiplying each pair of

and its

and add up the answers
E(X) = (0×0.7) + (1×0.2) + (2×0.1) = 0.4
The formula to calculate the variance, Var(X), is given by E(X)² - (E(X))²
E(X²) = (0²×0.7) + (1²×0.2) + (2²×0.1) = 0+0.2+0.4 = 0.6
(E(X))² = (0.4)² = 0.16
Var(X) = 0.6 - 0.16 = 0.44
Translating these answers into the context we have
E(Y) = 0.4×500 = $200
Var(Y) = $110
About 15 because 9 times 5 = 45 reminder 3 than you add 3 times 5 = 15
A) get rid of the fraction by finding the common denominator, 4. multiplying by 4 on both sides, I usually have it turned into a fraction, 4/1. The 2x=3/4, is now 8x=12/4 will be set as 8x=3. Divide 8, x=3/8.
B) The common denominator is 15. Multiply on both sides, -2/5 times 15/1 is -30/5 which becomes -6. And m/3 times 15/1 is 15m/3, 5m. divide the 5 and your answer is m=-5/6
the solutions to a general quadratic equation is
X=-b±√b²-4ac/2a ,, When ax²+bx+c=0
the discriminant is the expression under the radical b²−4ac
Part A:
discriminant is (-16)² - 4(9)(60) = -1904
there are two complex solutions
Part B:
4x² + 8x − 5 = 0
4x² + 10x -2x - 5=0
2x ( 2x + 5) - 1(2 x + 5) =0
(2x + 5)(2x-1) = 0
/ \
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2x+5 = 0 2x-1 =0
x = -5/2 x = 1/2