Show that, when sampling with replacement and when each population element has an equal chance of being selected for the sample, s^2/n is an unbiased estimator for Var(X).
(where s^2 =1/(n−1) Pni=1(Xi − X)^2)
Show that, when sampling with replacement and when each population element has an equal chance of...
1. Select all true statements about sample mean and sample median. A) When the population distribution is skewed, sample mean is biased but sample median is an unbiased estimator of population mean. B) When the population distribution is symmetric, both mean and sample median are unbiased estimators of population mean. C) Sampling distribution of sample mean has a smaller standard error than sample median when population distribution is normal. D) Both mean and median are unbiased estimators of population mean...
CLUSTER SAMPLING WITH ESTIMATION Suppose a population of size N is divided into K- N/M groups of size M. We select a sample of size n -km the following way: » First we select k groups out of K groups by simple random sampling . We then select m units in each group selected on the first step by simple random sampling . The estimate of the population mean is the average Y of the sample. Let μί be the...
In simple random sample every member of the population has a known and equal chance of being selected, but you cannot calculate sampling error. * true or false
Q1. In a population with N= 6 the values of yi are 8, 3, 1, 11, 4, and 7. Draw all possible ordered samples of size 2 from this population without replacement (i) Find the population mean (ii) Find P(s) for each sample point. (iii) Find T, for each unit. (iv)Find the sampling distribution of v (v) Show that is an unbiased estimator of F (vi) Show that V(F) (vii) Show that s 2 is an unbiased estimator of σ2
Q1. In a population with N= 6 the values of yi are 8, 3, 1, 11, 4, and 7. Draw all possible ordered samples of size 2 from this population without replacement (i) Find the population mean (ii) Find P(s) for each sample point. (iii) Find T, for each unit. (iv)Find the sampling distribution of v (v) Show that is an unbiased estimator of F (vi) Show that V(F) (vii) Show that s 2 is an unbiased estimator of σ2
5. Horvitz-Thompson (HT) estimator (a) (2 marks) Show that the HT estimator es tu/su is unbiased for the population total. Clearly define any notation used. (b) (1 mark) The variance of the HT estimator is Var(ār(s)) = () Give the HT estimate of the variance based on the sample, S. (c) (1 mark) Suppose we sample with replacement where probability of selecting unit u is pu. Derive the inclusion probability for unit. (d) A sample (n = 6) was randomly...
Consider a family of four people, aged 8, 10, 33, and 37 as a population a) Calculate the population variance and standard deviation for the ages. Show your work step by step b) Random samples of size two are drawn with replacement from this population and their ages are recorded Find the variance and standard deviation for each sample (using the formula that involves divisions by n-1) and fill in the 3rd and 4th columns of the table Find the...
x, and S1 are the sample mean and sample variance from a population with mean μ| and variance ơf. Similarly, X2 and S1 are the sample mean and sample variance from a second population with mean μ and variance σ2. Assume that these two populations are independent, and the sample sizes from each population are n,and n2, respectively. (a) Show that X1-X2 is an unbiased estimator of μ1-μ2. (b) Find the standard error of X, -X. How could you estimate...
For the population of N = 5 units of Exercise 3 of Chapter 2
(a) Compute directly the variance var (y) of the sample mean and
the variance var( m ) of the sample median.
(b) From each sample, compute the sample variance s 2 and the
estimate var (y) of the variance of the sample mean. Show that the
sample variance s 2 is unbiased for the √ finite-population
variance σ 2 but that the sample standard deviation 2...
In a population with N-6 the values of y are 8, 3, 1, 11, 4, and 7. Draw all possible unordered sam ples of size 4 from this population without replacement. (i) Find P(s) for each sample point (ii) Find T, for each unit. (ii) Find the sampling distribution of v. (iv) Is y an unbiased estimator of ? Justify your answer. ()Is V(F)- (1- Justify your answer. 72 () Is r an unbiased estimator of s? Justify your answer.