


PROBLEM 1: Assume you have a random sample of Y's of size n from the model...
(1) True or False: Please specify your reasons. (i) An estimator is unbiased, if its expected value across different samples equals to the true value of the parameter. (ii) OLS estimator is always unbiased. (iii) We can use n- i-, û to estimate the error variance o2 because it is unbiased. (iv) If the sample size increases, we can have a better estimates of sd(Bo) and sd(B1).
Suppose
that Y1 , Y2 ,..., Yn denote a random sample of size n from a
normal population with mean μ and variance 2 .
Problem # 2: Suppose that Y , Y,,...,Y, denote a random sample of size n from a normal population with mean u and variance o . Then it can be shown that (n-1)S2 p_has a chi-square distribution with (n-1) degrees of freedom. o2 a. Show that S2 is an unbiased estimator of o. b....
1. Consider a variable y = θ+e where θ is an unknown parameter and e is a random variable with mean zero (a) What is the expected value of y (b) Suppose you draw a sample of in y-Derive the least squares estimator for θ. For full credit you must check the 2nd order condition. (c) Can this estimator () be described as a method of moments estimator? (d) Now suppose e is independent normally distributed with mean 0 and...
QUESTION 3 Let Y1, Y2, ..., Yn denote a random sample of size n from a population whose density is given by (Parcto distribution). Consider the estimator β-Yu)-min(n, Y, where β is unknown (a) Derive the bias of the estimator β. (b) Derive the mean square error of B. , Yn).
We have a random sample of size 17 from the normal distribution N(u,02) where u and o2 are unknown. The sample mean and variance are x = 4.7 and s2 = 5.76 (a) Compute an exact 95% confidence interval for the population mean u (b) Compute an approximate (i.e. using a normal approximation) 95% confidence interval for the population mean u (c) Compare your answers from part a and b. (d) Compute an exact 95% confidence interval for the population...
I. Consider a variable y = θ + where θ is an unknown parameter and e is a random variable with mean zero. (a) What is the expected value of y? (b) Suppose you draw a sample of yi yn. Derive the least squares estimator for θ. For full credit you must check the 2nd order condition c) Can this estimator (0) be described as a method of moments estimator? (d) Now suppose є is independent normally distributed with mean...
Suppose you have a random sample {X1, X2, X3} of size n = 3. Consider the following three possible estimators for the population mean u and variance o2 Дi 3D (X1+ X2+ X3)/3 Ti2X1/4 X2/2 X3/4 Дз — (Х+ X,+ X3)/4 (a) What is the bias associated with each estimator? (b) What is the variance associated with each estimator? (c) Does the fact that Var(i3) < Var(1) contradict the statement that X is the minimum variance unbiased estimator? Why or...
where p denote the population mean of the original random variable 5.7 Problems . Assume X is a normally distributed random variable with mean u and stan- dard deviation σ. A sample of size n-5 from this distribution is given as 1. Assume we are interested in the properties of the mean of the sam- pling distribution of the sample mean. Describe why this quantity is a 2. State an estimator for the parameter given in question 1. Use this...
We are given that n=15, the sample mean Ῡ=2.5, the sample standard deviation s=1.5 and random variable Y distributed Normal with mean µ and variance σ2, where both µ and σ2 are unknown and we are being concentrated on testing the following set of hypothesis about the mean parameter of the population of interest. We are to test: H0 : µ ≥ 3.0 versus H1 : µ < 3.0. Compute the following: a) P- value of the test b) ...
QUESTION 2 Let Xi.. Xn be a random sample from a N (μ, σ 2) distribution, and let S2 and Š-n--S2 be two estimators of σ2. Given: E (S2) σ 2 and V (S2) - ya-X)2 n-l -σ (a) Determine: E S2): (l) V (S2); and (il) MSE (S) (b) Which of s2 and S2 has a larger mean square error? (c) Suppose thatnis an estimator of e based on a random sample of size n. Another equivalent definition of...