X and Y are independent normally distributed random variables with respective means 4 & 5, and respective SD's 3 & 8. Determine P( 2X > Y+ 9). Explain each step please
X and Y are independent normally distributed random variables with respective means 4 & 5, and...
6.48 Two Gaussian random variables, X and Y, are in- dependent. Their respective means are 4 and 2, and their respective variances are 3 and 5 (a) Write down expressions for their marginal pdfs. (b) Write down an expression for their joint pdf. (c) What is the mean of Z 3X +Y? Z, 3X- Y? (d) What is the variance of Z = 3X + Y? Z, 3X-Y? (e) Write down an expression for the pdf of Z1 3X+Y
Problem D: Suppose X1, .,X, are independent random variables. Let Y be their sum, that is Y 1Xi Find/prove the mgf of Y and find E(Y), Var(Y), and P (8 Y 9) if a) X1,.,X4 are Poisson random variables with means 5, 1,4, and 2, respectively. b) [separately from part a)] X,., X4 are Geometric random variables with p 3/4. i=1
X and Y are independent random variables with respective PDFs given by: ??(?) = ?? −?? , ? > 0, ? > 0, and ?? (?) = ?? −?? , ? > 0, ? > 0. Assume random variable ? = ? + ?, find the PDF of the random variable V
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?
10. (5pt) Suppose that X and Y are two normally distributed random variables. X has mean 2 and standard deviation !5 Y has mean 5 and standard deviation 3. Their correlation is 0.6. What is the mean and standard deviation of X + Y? What is the distribution of X+ Y? What if X and Y are jointly normally distributed? What if they are not jointly normally distributed? Explain your answer.
6. Consider a sample X,... X, of normally distributed random variables with mean y and variance op. Let 5 be the sample variance and suppose that n = 16. What is the value of c for which p[x - SS (C2 - 1)] = 95 ? be the 7. Consider a sample X,...,X, of normally distributed random variables with variance o? = 30. Let S sample variance and suppose that n-61. What is the value of c for which P...
33. Let X and Y be independent exponential random variables with respective rates λ and μ. (a) Argue that, conditional on X> Y, the random variables min(X, Y) and X -Y are independent. (b) Use part (a) to conclude that for any positive constant c E[min(X, Y)IX > Y + c] = E[min(X, Y)|X > Y] = E[min(X, Y)] = λ+p (c) Give a verbal explanation of why min(X, Y) and X - Y are (unconditionally) independent.
33. Let X...
Let X and Y denote independent random variables with respective probability density functions, f(x) = 2x, 0<x<1 (zero otherwise), and g(y) = 3y2, 0<y<1 (zero otherwise). Let U = min(X,Y), and V = max(X,Y). Find the joint pdf of U and V.
Problem 5. (2 points) If X,, X, ..X40 are independent random variables with means u, = 2 = ... = H40 = 1, and variances o? = o? = o%o = 1, and if Y = 2X, – 3X, +X3 + X4 + ..+X40 , What are the mean and = ... variance of Y?
The difference of two independent normally distributed random
variables is also normally distributed. We have used this fact in
many of our derivations. Now, consider two independent and normally
distributed populations with unknown variances σ 2 X and σ 2 Y . If
we get a random sample X1, X2, . . . , Xn from the first population
and a random sample Y1, Y2, . . . , Yn from the second population
(note that both samples are of...