Question

In: Statistics and Probability

5. Suppose that X and Y have the following joint probability distribution: f(x,y) x 2 4...

5. Suppose that X and Y have the following joint probability distribution:

f(x,y)

x

2

4

y

1

0.10

0.15

2

0.20

0.30

3

0.10

0.15

Find the marginal distribution of X and Y.

Find the expected value of g(x,y) = xy2 or find E(xy2).

Find (x and (y.

Find Cov(x,y)

Find the correlations ρ(x,y)

3.

The length of life X, in days, of a heavily used electric motor has probability density function

Find the probability that the motor has at least 1/2 of a day, given that it has lasted 1/4 of a day.

Find the mean and the variance for X.

Solutions

Expert Solution


Related Solutions

Question 3 Suppose that X and Y have the following joint probability distribution: f(x,y) x 0...
Question 3 Suppose that X and Y have the following joint probability distribution: f(x,y) x 0 1 2 y 0 0.12 0.08 0.06 1 0.04 0.19 0.12 2 0.04 0.05 0.3 Find the followings: E(Y)= Var(X)= Cov(X,Y)= Correlation(X,Y)=
If the joint probability distribution of X and Y f(x, y) = (x + y)/2
If the joint probability distribution of X and Y f(x, y) = (x + y)/2, x=0,1,2,3; y=0,1,2, Compute the following a. P(X≤2,Y =1) b. P(X>2,Y ≤1) c. P(X>Y) d. P(X+Y=4)
Suppose that X and Y have the following joint probability density function. f (x, y) =...
Suppose that X and Y have the following joint probability density function. f (x, y) = (3/394)*y, 0 < x < 8, y > 0, x − 3 < y < x + 3 (a)   Find E(XY). (b)   Find the covariance between X and Y.
Determine the correlation for the following joint probability distribution: x 2 4 2 4 y 3...
Determine the correlation for the following joint probability distribution: x 2 4 2 4 y 3 4 5 6 fx,y(x,y) 1/8 1/4 1/2 1/8 a. Correlation = 0.6387 b. Correlation = 0.0377 c. Correlation = 0.3737 d. Correlation = 0.8023
Suppose the joint probability distribution of X and Y is given by the following table. Y=>3...
Suppose the joint probability distribution of X and Y is given by the following table. Y=>3 6 9 X 1 0.2 0.2 0 2 0.2 0 0.2 3 0 0.1 0.1 The table entries represent the probabilities. Hence the outcome [X=1,Y=6] has probability 0.2. a) Compute E(X), E(X2), E(Y), and E(XY). (For all answers show your work.) b) Compute E[Y | X = 1], E[Y | X = 2], and E[Y | X = 3]. c) In this case, E[Y...
Suppose that the joint probability density function of ˜ (X, Y) is given by:´ f X,Y...
Suppose that the joint probability density function of ˜ (X, Y) is given by:´ f X,Y (x,y) = 4x/y3 I(0.1)(x), I (1, ∞)(y). Calculate a) P(1/2 < X < 3/4, 0 < Y ≤ 1/3). b) P(Y > 5). c) P(Y > X).
Suppose X and Y have joint probability density function f(x,y) = 6(x-y) when 0<y<x<1 and f(x,y)...
Suppose X and Y have joint probability density function f(x,y) = 6(x-y) when 0<y<x<1 and f(x,y) = 0 otherwise. (a) Indicate with a sketch the sample space in the x-y plane (b) Find the marginal density of X, fX(x) (c) Show that fX(x) is properly normalized, i.e., that it integrates to 1 on the sample space of X (d) Find the marginal density of Y, fY(y) (e) Show that fY(y) is properly normalized, i.e., that it integrates to 1 on...
Suppose that we have two random variables (Y,X) with joint probability density function f(y,x). Consider the...
Suppose that we have two random variables (Y,X) with joint probability density function f(y,x). Consider the following estimator of the intercept of the Best Linear Predictor: A = ?̅ - B • ?̅ , where ?̅ is the sample mean of y, ?̅ is the sample mean of x, and B is the sample covariance of Y and X divided by the sample variance of X. Identify the probability limit of A (if any). For each step in your derivation,...
2) X and Y have the following joint probability density function: n=4, X=2, Y=1, Z=3 Find:...
2) X and Y have the following joint probability density function: n=4, X=2, Y=1, Z=3 Find: a)Marginal distribution of X and Y. b)Mean of X and Y. c)E(XY). d)Covariance of X and Y and comment on it. e)Correlation coefficient between X and Y. And comment. 2) X and Y have the following joint probability density function: {((5y^3)/(96x^2)) 2<x<5, 0<y<4             0      Elsewhere} Find: a) Marginal distribution of X and Y b) Mean of X and Y c) E(XY) d)...
Consider the following joint distribution. X p(x,y) 2 5 Y 2 0.1 0.34 5 0.31 0.25...
Consider the following joint distribution. X p(x,y) 2 5 Y 2 0.1 0.34 5 0.31 0.25 Based on this distribution, find: E(X) Sd(Y) Corr(X,Y)
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT