Q1. Which of the following statements about sampling and estimation is most accurate? A) A point estimate is a single estimate of an unknown population parameter calculated as a sample mean. B) A confidence interval estimate consists of a range of values that bracket the parameter with a specified level of probability, 1 − β. C) Time-series data are observations over individual units at a point in time.
Q2. Which of the following statements about sampling and estimation is most accurate? A) The standard error of the sample means when the standard deviation of the population is unknown equals s / √n, where s = sample standard deviation. B) The probability that a parameter lies within a range of estimated values is given by α. C) The standard error of the sample means when the standard deviation of the population is known equals σ / √n, where σ = sample standard deviation adjusted by n − 1.
Q3. A range of estimated values within which the actual value of a population parameter will lie with a given probability of 1 − α is a(n): A) (1 − α) percent confidence interval. B) α percent confidence interval. C) α percent point estimate.
Q4. Which of the following characterizes the typical construction of a confidence interval correctly? A) Standard error +/- (Point estimate / Reliability factor). B) Point estimate +/- (Reliability factor x Standard error). C) Point estimate +/- (Standard error / Reliability factor).
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发表于 2009-1-9 11:01
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