Let X1, X2, X3, and X4 be a random sample of observations from a population with mean μ and variance σ2. Consider the following estimator of μ: 1 = 0.15 X1 + 0.35 X2 + 0.20 X3 + 0.30 X4. Using the linear combination of random variables rule and the fact that X1, ..., X4are independently drawn from the population, calculate the variance of 1?
0.55 σ2
0.275 σ2
0.125 σ2
0.20 σ2
Let X1, X2, X3, and X4 be a random sample of observations from a population with...
7.Let X1, X2, X3, and X4 be a random sample of observations from a population with mean μ and variance σ2. Consider the following estimator of μ:⊝1 = 0.15 X1 + 0.35 X2 + 0.20 X3 + 0.30 X4. Is this a biased estimator for the mean? What is the variance of the estimator? Can you find a more efficient estimator?
Let X1, X2, X3, and X4 be a random sample of observations from a population with mean μ and variance σ2. The observations are independent because they were randomly drawn. Consider the following two point estimators of the population mean μ: 1 = 0.10 X1 + 0.40 X2 + 0.40 X3 + 0.10 X4 and 2 = 0.20 X1 + 0.30 X2 + 0.30 X3 + 0.20 X4 Which of the following statements is true? HINT: Use the definition of...
If a null hypothesis is rejected at a significance level of 1%, then we should say that it was rejected at 1%. Reporting that the null was also rejected at the 5% level of significance is unnecessary and unwise. True False The p-value equals alpha, the level of significance of the hypothesis test. True False THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Let X1, X2, X3, and X4 be a random sample of observations from a population with...
please answer the questions easily Suppose X1, X2, X3 is a random sample from a normal population with mean μ and variance (a) I,'ind i.he variallex, of Y , x..:.: Xy/X.t as an ( tinai." r of μ (b) Find the variance of Z-A+x2+x3 as an estimator of μ. (c) Which estimator is more efficient (i.e. has the smallest variance)? Consider a random sample of size n from a normal population with known mean μ and unknown variance σ2. Let...
Let x1, x2,x3,and x4 be a random sample from population with normal distribution with mean ? and variance ?2 . Find the efficiency of T = 1/7 (X1+3X2+2X3 +X4) relative to x= x/4 , Which is relatively more efficient? Why?
Let X1, X2, X3, X4 be a random sample from a standard normal population. What is the probability distribution (give the name of the distribution and the value of any parameter(s)) of (a). (X1 - Xbar)^2 + (X2 - Xbar)^2 + (X3 - Xbar)^2 + (X4 - Xbar)^2 (b). ((X1 + X2 + X3 + X4)^2)/4
Let X1, X2, X3 be independent random variables with E(X1) = 1, E(X2) = 2 and E(X3) = 3. Let Y = 3X1 − 2X2 + X3. Find E(Y ), Var(Y ) in the following examples. X1, X2, X3 are Poisson. [Recall that the variance of Poisson(λ) is λ.] X1, X2, X3 are normal, with respective variances σ12 = 1, σ2 = 3, σ32 = 5. Find P(0 ≤ Y ≤ 5). [Recall that any linear combination of independent normal...
Let X1,X2,X3,X4 be observations of a random sample of n-4 from the exponential distribution having mean 5, What is the mgf of Y-X1 X2 X3 X4? 4. 5. What is the distribution of Y? What is the mgf of the sample mean X = X+X+Xa+X1 ? 6. 7. What is the distribution of the sample mean?
Let X1,X2,X3,X4 be four Normal(μ=1,σ=1) variables. Calculate Pr(X1−X2>X3+X4)
Suppose you have a sample of n independent observations X1,X2,...,Xn from a normal population with mean μ (known) and variance σ2 (unknown). (a) Find the ML estimator of σ2 . (b) Show that the ML estimator in (a) is a consistent estimator of θ. (c) Find a sufficient statistic for σ2. (d) Give a MVUE for θ based on the sufficient statistic.