Problem 1: confidence interval for a variance parameter for a normal distribution
Let Ybe a normal random variable with mean μand variance σ2. Assume that μis known but σ2is unknown. Show that ((Y-μ)/σ)2is a pivotal quantity. Use this pivotal quantity to derive a 1-α confidence interval for σ2. (The answer should be left in terms of critical values for the appropriate distribution.)
Problem 1: confidence interval for a variance parameter for a normal distribution Let Ybe a normal...
Let X1,X2, , Xn be a random sample from a normal distribution with a known mean μ (xi-A)2 and variance σ unknown. Let ơ-- Show that a (1-α) 100% confidence interval for σ2 is (nơ2/X2/2,n, nơ2A-a/2,n). Let X1,X2, , Xn be a random sample from a normal distribution with a known mean μ (xi-A)2 and variance σ unknown. Let ơ-- Show that a (1-α) 100% confidence interval for σ2 is (nơ2/X2/2,n, nơ2A-a/2,n).
Let Ybe a normal random variable with parameters (1,a2). In other words, its mean is 1 while its variance a2 is unknown. Find 95% upper one-sided confidence interval for a2 in terms of Y Let Ybe a normal random variable with parameters (1,a2). In other words, its mean is 1 while its variance a2 is unknown. Find 95% upper one-sided confidence interval for a2 in terms of Y
6. Let Xi 1,... ,Xn be a random sample from a normal distribution with mean u and variance ơ2 which are both unknown. (a) Given observations xi, ,Xn, one would like to obtain a (1-a) x 100% one-sided confidence interval for u as a form of L E (-00, u) the expression of u for any a and n. (b) Based on part (a), use the duality between confidence interval and hypothesis testing problem, find a critical region of size...
6.29. Let Xi, X2, , X,be a random sample from a gamma distribution with known parameter α-3 and unknown β > 0,' Discuss the construction of a confidence interval for B. Hint: what is the distribution of 2 Σ x/P Follow the procedure outlined in Exercise 6.28. 6.29. Let Xi, X2, , X,be a random sample from a gamma distribution with known parameter α-3 and unknown β > 0,' Discuss the construction of a confidence interval for B. Hint: what...
8.40 stion 4 (6 pt) (Ex. 8.40 on page 409 is modified): Suppose that random variable Y is an observation from a normal distribution with unknown mean u and variance l Find and verify a pivotal quantity that you can use to derive confidence limits for the mean u. Find a 95% lower confidence limit for. a. b. 8.40 Suppose that the random variable Yis an observation from a normal distribution with unknown mean μ and variance 1 . Find...
A sample of 27 independent observations is taken from a normal distribution of unknown mean μ but known variance σ. 75.24. The sample mean is 5 is the width of the 98% confidence interval for μ? 4.42 and the sample variance is 41. What A sample of 27 independent observations is taken from a normal distribution of unknown mean μ but known variance σ. 75.24. The sample mean is 5 is the width of the 98% confidence interval for μ?...
A new diet that promises a fast loss of weight is launched. The change in weight after a week on the diet is modelled using a Normal distribution with mean u and variance σ2. Let z, . . . , zn be an independent sample from this Normal. (a) Knowing that μ z, find the method of moments estimator for σ. [4] (b) State (without deriving) an alternative estimator you know for σ2. Give one reason why one would prefer...
1. (40) Suppose that X1, X2, Xn forms an independent and identically distributed sample from a normal distribution with mean μ and variance σ2, both unknown: 2nơ2 (a) Derive the sample variance, S2, for this random sample. (b) Derive the maximum likelihood estimator (MLE) of μ and σ2 denoted μ and σ2, respectively. (c) Find the MLE of μ3 (d) Derive the method of moment estimator of μ and σ2, denoted μΜΟΜΕ and σ2MOME, respectively (e) Show that μ and...
please answer with full soultion. with explantion. (4 points) Let Xi, , Xn denote a randon sample from a Normal N(μ, 1) distribution, with 11 as the unknown parameter. Let X denote the sample mean. (Note that the mean and the variance of a normal N(μ, σ2) distribution is μ and σ2, respectively.) Is X2 an unbiased estimator for 112? Explain your answer. (Hint: Recall the fornula E(X2) (E(X)Var(X) and apply this formula for X - be careful on the...
Problem 5 of 5Sum of random variables Let Mr(μ, σ2) denote the Gaussian (or normal) pdf with Inean ,, and variance σ2, namely, fx (x) = exp ( 2-2 . Let X and Y be two i.i.d. random variables distributed as Gaussian with mean 0 and variance 1. Show that Z-XY is again a Gaussian random variable but with mean 0 and variance 2. Show your full proof with integrals. 2. From above, can you derive what will be the...