Reading and Comprehension Questions for Chapter 7
1. A statistic is a function of the observations in a random sample.
True False
True
2. The probability distribution of a statistic is called a sampling distribution.
True False
True
3. All of the observations in a random sample are independent.
True False
True
4. The sampling distribution of the sample mean is the t distribution.
True False
False – the sampling distribution of the sample mean is the normal distribution.
5. The central limit theorem states that the distribution of the sum of independent random
variables is the normal distribution.
True False
True
6. The variance of the difference between two independent random variables is the
difference in the variances of the two individual random variables.
True False
False – the variance of the difference between two independent random variables is the
sum of the variances of the two individual random variables.
7. A point estimator of an unknown parameter is unbiased if the expected value of the
estimator equals the parameter.
True False
True
8. The sample mean and sample variance are unbiased estimators of the corresponding
population parameters.
True False
True
9. The sample standard deviation is an unbiased estimator of the population standard
deviation.
True False
False
10. The standard error of a point estimator is a measure of the accuracy of the estimator.
True False
False – the standard error is a measure of precision of estimation.
11. The mean square error of a point estimator includes a variance component and a bias
component.
True False
True
12. The sample mean is a moment estimator of the population mean.
True False
True
13. The sample mean is the maximum likelihood estimator of the mean in the normal
distribution.
True False
True
14. The method of maximum likelihood always results in unbiased estimators.
True False
False
15. The method of maximum likelihood is usually the preferred method for finding point
estimators because it produces estimators that have good statistical properties.
True False
True
16. The Bayesian approach to finding a point estimator of an unknown parameter
involves treating the unknown parameter as a random variable.
True False
True