a. statastics uses probability as probability is essential tool in statastics. the concept is important as it misunderstand .it have an understanding nature of change and variation in life in order to be well informed citizens.
b.
1. Fundamentals: (a) Briefly, state why probability is important for statisticians (b) Let random variables X,...
Let X, Y, Z be random variables. Prove or disprove the following statements. (That means, you need to either write down a formal proof, or give a counterexample.) (a) If X and Y are (unconditionally) independent, is it true that X and Y are conditionally indepen- dent given Z? (b) If X and Y are conditionally independent given Z, is it true that X and Y are (unconditionally) independent?
5. Let X, Y, Z be random variables with joint density (discrete or continuous) plr, y,a) a f(x, 2)g(y, 2)h() Show that (a) p(rly, s) x /(r, :), ie. P(rly, :) is a function of 1 and :; (b) p(y|z, z) g(y, z), İ.e. p(y|z,z) is a function of y and z; (c) X and Y are conditionally independent given Z
Suppose X, Y and Z are three different random variables. Let X obey Bernoulli Distribution. The probability distribution function is p(x) = Let Y obeys the standard Normal (Gaussian) distribution, which can be written as Y ∼ N(0, 1). X and Y are independent. Meanwhile, let Z = XY . (a) What is the Expectation (mean value) of X? (b) Are Y and Z independent? (Just clarify, do not need to prove) (c) Show that Z is also a standard...
(1 point) 3. Let X and Y be random variables with a joint probability density function f(z, y)e (a)Find the marginal distribution functions of X and Y, respectively. i.e. Find f(z) and f(y) f(x)- elsewhere (b) Identify the distribution of Y. What is the E(Y) and SD(Y) E(Y)- (c) Are X and Y independent random variables? Show why, or why not (d) Find P(1 X 2|Y 1) E SD(Y)-
2. Let X and Y be independent, exponentially distributed random variables where X has mean 1/λ and Y has mean 1/μ. (a) What is the joint p.d.f of X and Y? (b) Set up a double integral for determining Pt <X <Y) (c) Evaluate the above integral. (d) Which of the following equations true, and which are false? {Z > t} = {X > t, Y > t} (e) Compute P[Z> t) wheret 0. (f) Compute the p.d.f. of Z.
Question 1 、 Let X, Y and Z be three random variables that take values in the alphabet {0,1, M-lj. We assume X and Z are independent and Y = X +2(mod M), The distribution of Z is given as P(Z 0)1 -p and P (Z =i)= , for i = 1, M-1. For question 1-3 we M-1 will assume that X is uniform on f0,1,..,M-1}. Find H(X) and H(Z) Find H(Y ) Find 1 (X; Y) and「X, YZ) and...
2) Two statistically-independent random variables, (X,Y), each have marginal probability density, N(0,1) (e.g., zero-mean, unit-variance Gaussian). Let V-3X-Y, Z = X-Y Find the covariance matrix of the vector, 2) Two statistically-independent random variables, (X,Y), each have marginal probability density, N(0,1) (e.g., zero-mean, unit-variance Gaussian). Let V-3X-Y, Z = X-Y Find the covariance matrix of the vector,
Let X and Y be jointly continuous random variables with joint probability density given by f(x, y) = 12/5(2x − x2 − xy) for 0 < x < 1, 0 < y < 1 0 otherwise (a) Find the marginal densities for X and Y . (b) Find the conditional density for X given Y = y and the conditional density for Y given X = x. (c) Compute the probability P(1/2 < X < 1|Y =1/4). (d) Determine whether...
Let X and Y be jointly continuous random variables with joint probability density given by f(x, y) = 12/5(2x − x2 − xy) for 0 < x < 1, 0 < y < 1 0 otherwise (a) Find the marginal densities for X and Y . (b) Find the conditional density for X given Y = y and the conditional density for Y given X = x. (c) Compute the probability P(1/2 < X < 1|Y =1/4). (d) Determine whether...
Which of the following statements are true and false? Prove the trueones and give counterexamples for the false ones. Let X and Z be random variables.(i) If X and Z are uncorrelated, then they are independent.(ii) If X and Z are independent, then E[X2] = E[Z2].(iii) If X and Z are correlated, they are also dependent.