The independent would be the base amount (0.25 in this case) The dependent would be :
the sum of the minutes x 0.25 or the entire phone bill
Answer:
132in
Step-by-step explanation:
Answer:
D. The solution is (8, 2).
Step-by-step explanation:
x - 2y = 4
5x -3y = 34 Multiply the first equation by 5:
5x - 10y = 20 Subtract:
0 + 7y = 14
y = 2.
Substitute for y in the first equation:
x - 2*2 = 4
x = 4+4 = 8.
Answer:
a) Mean is -23.47
b) Variance is 206.59
c) standard deviation is 14.37
Step-by-step explanation:
Given that;
x −41 −27 −8 −3
P(X = x) 0.29 0.35 0.21 0.15
X.P -11.89 -9.45 -1.68 -0.45
a) mean
Mean = ∑X.P = -11.89 + -9.45 + -1.68 + -0.45
Mean = -23.47
b) the variance
E(x²) = ∑x²P(X=x)
= (−41²×0.29) + (−27²×0.35) + (−8²×0.21) + (−3²×0.15)
= 487.49 + 255.15 + 13.44 + 1.35
= 757.43
So
Var(X) = E(x²) - [∑X.P]²
Var(X) = 757.43 - [-23.47]²
= 757.43 - 550.8409
= 206.5891 ≈ 206.59
Therefore Variance is 206.59
c) standard deviation
standard deviation SD(X) = √Var(X)
SD(X) = √206.5891
= 14.3732 ≈ 14.37
Therefore standard deviation is 14.37