Exercise 2 (2). Let X and ε be independent normally distributed
random variables such that X∼N(5,4)andε∼N(0,9).LetY
bearandomvariablegivenbyY =1+2X+ε.Compute: (a) E(Y )
(b) Var(Y )
(c) Cov(X, Y )
(d) Corr(X, Y )
(e) What is the value of the ratio Cov(X, Y )/Var(X) ?
(f) If Y = 1 + 3X + ε instead, what would be the value of Cov(X, Y
)/Var(X) ? (g) If Y = 1 + 7X + ε instead, what would be the value
of Cov(X, Y )/Var(X) ?
Exercise 2 (2). Let X and ε be independent normally distributed random variables such that X∼N(5,4)andε∼N(0,9).LetY...
9. Let X and Y be independent and identically distributed random variables with mean u and variance o. Find the following: (a) E[(x + 2)] (b) Var(3x + 4) (c) E[(X-Y)] (d) Cov{(X + Y), (X - Y)}
Let X1 and X2 be independent random variables with means μ1 and μ2, and variances σ21 and σ22, respectively. Find the correlation of X1 and X1 + X2. Note that: The covariance of random variables X; Y is dened by Cov(X; Y ) = E[(X - E(X))(Y - E(Y ))]. The correlation of X; Y is dened by Corr(X; Y ) =Cov(X; Y ) / √ Var(X)Var(Y )
Can someone help me with this? Show that two jointly normally distributed random variables are independent if they are uncorrelated? Additional Info: Thank's a lot!!! Let (*) ~ ~[(*) (*)) with oš> 0, 0} > 0. NX Then YlX^N (wy +O20yx(– Hx), oz, – 022Oxy@yx). That is, the regression function is here linear (in X): E[Y|X] = E[Y]+B(X – E[X]) = Hy +B(X – Hx), where B = Cov(X, Y) = pºy; recall: =vx= POD Cov(X, Y) = Oxy =...
(Sums of normal random variables) Let X be independent random variables where XN N(2,5) and Y ~ N(5,9) (we use the notation N (?, ?. ) ). Let W 3X-2Y + 1. (a) Compute E(W) and Var(W) (b) It is known that the sum of independent normal distributions is n Compute P(W 6)
Let X, Y, Z be random variables with these properties: · E[X] = 3 and E[X²] = 10 Var(Y) = 5 E[Z] = 2 and E[Z2] = 7 • X and Y are independent E[X2] = 5 Cov(Y,Z) = 2 Find Var(3X+Y – Z).
1. Let X,.., Xn be independent and identically distributed as N (0,9) (here 9 is the variane (a) What is the distribution of Y-1X,? (Verify it using MGF) (b) What is the distribution of Xn X? (Again verify it using MGF) (c) Assume n -25. What is the probability that an observed value of X lies inside the interval [-1.2,1.2] (d) Give a lower bound on the probability that Xn lies inside the interval1.2,1.2] using Chebyshev's inequality. Compare it with...
Exercise 1 (1). X, Y are random variables (r.v.) and a,b,c,d are values. Complete the formulas using the expectations E(X), E(Y), variances Var(X), Var(Y) and covariance Cov(X, Y) (a) E(aX c) (b) Var(aX + c (d) Var(aX bY c) (e) The covariance between aX +c and bY +d, that is, Cov(aX +c,bY +d) f) The correlation between X, Y that is, Corr(X,Y (g) The correlation between aX +c and bY +d, that is, Corr(aX + c, bY +d)
Let A, B, and C be independent random variables, uniformly distributed over [0,9], [0,2], and [0,3] respectively. What is the probability that both roots of the equation Ax^2+Bx+C=0 are real?
Let X and Y be two independent random variables. Show that Cov (X, XY) = E(Y) Var(X).
5. Suppose X is a normally distributed random variable with mean μ and variance 2. Consider a new random variable, W=2X + 3. i. What is E(W)? ii. What is Var(W)? 6. Suppose the random variables X and Y are jointly distributed. Define a new random variable, W=2X+3Y. i. What is Var(W)? ii. What is Var(W) if X and Y are independent?