Variance, estimator for mean, millionaire net worth
Not what you're looking for?
#1
Suppose you are sampling from a population with mean µ = 1,065 and standard deviation σ = 500. The sample size is n = 100. What are the expected value and the variance of the sample mean X? Show and explain your work (study guide # 5-41).
#2
Suppose a new estimator for the population mean is discovered. The new estimator is unbiased and has a variance equal to σ^2 / n^2 . Discuss the merits of the new estimator compared with the sample mean. Show and work and explain your answer (study guide # 5-65).
#3
Thomas Stanley, who surveyed 200 millionaires in the United States for his book The Millionaire Mind, found that those in that bracket had an average net worth of $9.2 million. The sample variance was 1.3 million $^2. Assuming that the surveyed subjects are a random sample of U.S. millionaires, give a 99% confidence interval for the average net worth of U.S. millionaires. Show and explain your work (study guide # 6-68).
#4
Use the following random sample of suitcase prices to construct a 90% confidence interval for the average suitcase price. Show and explain your answer (study guide # 6-84).
$285, $110, $495, $119, $125, $250, $320
Purchase this Solution
Solution Summary
Variance, estimator for mean and a millionaires net worth is examined.
Solution Preview
Four (4) Intro to Stats Problems
Please show all work and explain so I can compare to my work in order for me to find where I may be messing up. I am having trouble with variance so please be specific in this case. I really need to understand the concept, so please explain well.
#1
Suppose you are sampling from a population with mean µ = 1,065 and standard deviation σ = 500. The sample size is n = 100. What are the expected value and the variance of the sample mean X? Show and explain your work (study guide # 5-41).
Answer
From central limit theorem
Expected value of sample mean = Population mean = 1065
Variance of sample mean = =500/10 =50
#2
Suppose a new estimator for the population mean is discovered. The new estimator is unbiased and has a variance equal ...
Purchase this Solution
Free BrainMass Quizzes
Measures of Central Tendency
Tests knowledge of the three main measures of central tendency, including some simple calculation questions.
Terms and Definitions for Statistics
This quiz covers basic terms and definitions of statistics.
Measures of Central Tendency
This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.
Know Your Statistical Concepts
Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.