Suppose n numbers X1, X2, . . . , Xn are chosen from a uniform distribution on [0, 10]. We say that there is an increase at i if Xi < Xi+1. Let I be the number of increases. Find E[I].
The Uniform Distribution
This covers Uniform Distribution, Expectation and Variance, Proof of Expectation and Cumulative Distribution Function.
A continuous random variable X which has probability density function given by:
f(x) = 1 for a £
x £ b
b - a
(and f(x) = 0 if x is not between a and b) follows a uniform distribution with parameters a and b. We write X ~ U(a,b)
Remember that the area under the graph of the random variable must be equal to 1 (see continuous random variables).
Expectation and Variance
If X ~ U(a,b), then:
E(X) = ½ (a + b)
Var(X) = (1/12)(b - a)2
Proof of Expectation
Cumulative Distribution Function
The cumulative distribution function can be found by integrating the p.d.f between 0 and t:
Suppose n numbers X1, X2, . . . , Xn are chosen from a uniform distribution on [0, 10]. We say th...
7.6.4. Let X1, X2,... , Xn be a random sample from a uniform (0,) distribution. Continuing with Example 7.6.2, find the MVUEs for the following functions of (a) g(0)-?2, i.e., the variance of the distribution (b) g(0)- , i.e., the pdf of the distribution C) or t real, g(9)- , î.?., the mgf of the distribution. Example 7.6.2. Suppose X1, X2,... , Xn are iid random variables with the com- mon uniform (0,0) distribution. Let Yn - max{X1, X2,... ,...
Let X1, X2,.......Xn be a random sample of size n from a continuous distribution symmetric about . For testing H0: = 10 vs H1: < 10, consider the statistic T- = Ri+ (1-i), where i =1 if Xi>10 , 0 otherwise; and Ri+ is the rank of (Xi - 10) among |X1 -10|, |X2-10|......|Xn -10|. 1. Find the null mean and variance of T- . 2. Find the exact null distribution of T- for n=5. We were unable to transcribe this imageWe were...
a) Consider a random sample {X1, X2, ... Xn} of X from a uniform distribution over [0,0], where 0 <0 < co and e is unknown. Is п Х1 п an unbiased estimator for 0? Please justify your answer. b) Consider a random sample {X1,X2, ...Xn] of X from N(u, o2), where u and o2 are unknown. Show that X2 + S2 is an unbiased estimator for 2 a2, where п п Xi and S (X4 - X)2. =- п...
suppose X1 -> Xn is a random sample from a uniform distribution on the interval [0,theta]. let X1 = min {X1,X2,...Xn} and let Yn= nX1. show that Yn converges in distribution to an exponential random variable with mean theta.
Again, let X1,..., Xn be iid observations from the Uniform(0,0) distribution. (a) Find the joint pdf of Xi) and X(n)- (b) Define R = X(n)-X(1) as the sample range. Find the pdf of R. (c) It turns out, if Xi, . . . , xn (iid) Uniform(0,0), E(R)-θ . What happens to E® as n increases? Briefly explain in words why this makes sense intuitively.
Let t> 0 and let X1, X2, ..., Xn be a random sample from a Uniform distribution on interval (0,6t) a. Obtain the method of moments estimator of t, t. Enter a formula below. Use * for multiplication, / for division and ^ for power. Use m1 for the sample mean X. For example, 7*n^2*m1/6 means 7n2X/6. 提交答案 Tries 0/10 b. Find E(t). Enter a formula below E(i) 提交答案 Tries 0/10 c. Find Var(t). Enter a formula below. Var() 提交答案...
6. Let X1,..., Xn be a random sample from Uniform (0, 1). a) Find the exact distribution of U = – log(X(1)) where X(1) = min(X1, X2,..., Xn). b) Find the limiting distribution of n(1 – X(n)), where X(n) = max(X1, X2, ..., Xn).
4. Let X1,X2, ,Xn be a randonn sample from N(μ, σ2) distribution, and let s* Ση! (Xi-X)2 and S2-n-T Ση#1 (Xi-X)2 be the estimators of σ2 (i) Show that the MSE of s is smaller than the MSE of S2 (ii) Find E [VS2] and suggest an unbiased estimator of σ.
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?
2. Let X1, X2,. ., Xn be a random sample from a uniform distribution on the interval (0-1,0+1). . Find the method of moment estimator of θ. Is your estimator an unbiased estimator of θ? . Given the following n 5 observations of X, give a point estimate of θ: 6.61 7.70 6.98 8.36 7.26