Let Y1,…, Y18 be a random sample from a uniform distribution on the interval (0, θ], where θ is an unknown parameter we want to estimate. Two estimators for θ have been suggested:
θ_1 = max {Y1, ..., Y18} and θ _ 2 = 2Y¯ = 2 / 18 ∑i = 1, n =18, Yi
a) The expectation value of θ _1 and θ_2 can be expressed respectively E [θ_1] = k_1*θ and E [θ_2] = k_2*θ.
What is the value of k_1?
What is the value of k_2?
b) If the true value of θ is 1, what is the variance of that of the estimators that is the expectation right?
Let Y1,…, Y18 be a random sample from a uniform distribution on the interval (0, θ],...
Problem 2.1. Let Y1, ...,Yn be a random sample from a uniform distribution on the interval [0 – 1,20 + 1]. a. Find the density function of X = Y;-0 (note that Yi ~ Uf0 - 1,20 + 1]). b. Find the density function of Y(n) = max{Y;, i = 1,...,} c. Find a moment estimator of . d. Use the following data to obtain a moment estimate for 4: 11.72 12.81 12.09 13.47 12.37.
Let Y1, Y2, ..., Yn be independent random variables each having
uniform distribution on the interval (0, θ).
Find variance(Y(j) − Y(i))
Let Yİ,Y2, , Yn be independent random variables each having uniform distribu - tion on the interval (0,0) Fin ar(Y)-Yo
Suppose X1, X2, . . . , Xn are a random sample from a Uniform(0, θ) distribution, where θ > 0. Consider two different estimators of θ: R1 = 2X¯ R2 =(n + 1)/n max(X1, . . . , Xn) (a) For each of the estimators R1 and R2, assess whether it is an unbiased estimator of θ. (b) Compute the variances of R1 and R2. Under what conditions will R2 have a smaller variance than R1?
Let Y1 , Y2 , . . . , Yn denote a random sample from the uniform
distribution on the interval (θ, θ+1). Let
a. Show that both ? ̂1 and ? ̂2 are unbiased estimators of
θ.
2. [x] Suppose that Y1, Y2, Y3 denote a random sample from an exponential distribution whose pdf and cdf are given by f(y) = (1/0)e¬y/® and F(y) =1 – e-y/0, 0 > 0. It is also known that E[Y;] = 0. ', y > 0, respectively, with some unknown (a) Let X = min{Y1,Y2, Y3}. Show that X has pdf given by f(æ) = (3/0)e-3y/º. Start by thinking about 1- F(x) = Pr(min{Y1,Y2, Y3} > x) = Pr(Y1 > x,...
5. Let X1,.. ., Xn be a random sample from Uniform(0,0) with an unknown endpoint θ > 0, we want to estimate the parameter θ (a) Find the method of moments estimator (MME) of θ. (b) Find the MLE θ of θ (c) (R) Set the sample size as 25, do a simulation in R to compare these two esti- mators in terms of their bias and variance. Include a side-by-side boxplot that compares their sampling distributions
Let Y1, Y2, ..., Yn be independent random variables
each having uniform distribution on the interval (0, θ).
(a) Find the distribution of Y(n) and find its expected
value.
(b) Find the joint density function of Y(i) and Y(j) where 1 ≤ i
< j ≤ n. Hence
find Cov(Y(i)
, Y(j)).
(c) Find var(Y(j) − Y(i)).
Let Yİ, Ya, , Yn be independent random variables each having uniform distribu- tion on the interval (0, 6) (a) Find the distribution...
Let X,X,, X, be a random sample of size 3 from a uniform distribution having pdf /(x:0) = θ,0 < x < 0,0 < θ, and let):く,), be the corresponding order statistics. a. Show that 2Y, is an unbiased estimator of 0 and find its variance. b. Y is a sufficient statistic for 8. Determine the mean and variance of Y c. Determine the joint pdf of Y, and Y,, and use it to find the conditional expectation Find the...
1. Let Y1, . . . ,Y,, be a random sample from a population with density function 0, otherwise (a) Find the method of moments estimator of θ (b) Show that Yan.-max(Yi, . . . ,%) is sufficient for 02] (Hint: Recall the indicator function given by I(A)1 if A is true and 0 otherwise.) (c) Determine the density function of Yn) and hence find a function of Ym) that is an unbiased estimator of θ (d) Find c so...
taken from the uniform distribution on the interval [0,0] and that θ is unknown. How large a random sample must be taken in order that r max for all possible 9?