答案和详解如下： Q6. Which of the following statements about sampling errors is least accurate? A) Sampling errors are errors due to the wrong sample being selected from the population. B) Sampling error is the difference between a sample statistic and its corresponding population parameter. C) Sampling error is the error made in estimating the population mean based on a sample mean. Correct answer is A) Sampling error is the difference between a sample statistic (the mean, variance, or standard deviation of the sample) and its corresponding population parameter (the mean, variance, or standard deviation of the population). Q7. Sampling error is the: A) estimation error created by using a non-random sample. B) difference between the point estimate of the mean and the mean of the sampling distribution. C) difference between a sample statistic and its corresponding population parameter. Correct answer is C) Sampling error is the difference between any sample statistic (the mean, variance, or standard deviation of the sample) and its corresponding population parameter (the mean, variance or standard deviation of the population). For example, the sampling error for the mean is equal to the sample mean minus the population mean. Q8. From the entire population of McDonald’s franchises, an analyst constructs a sample of the monthly sales volume for 20 randomly selected franchises. She calculates the mean sales volume for those 20 franchises to be $400,000. The sampling distribution of the mean is the probability distribution of the: A) mean monthly sales volume estimates from all possible samples of 20 observations. B) mean monthly sales volume estimates from all possible samples. C) monthly sales volume for all McDonald’s franchises. Correct answer is A) The sampling distribution of a sample statistic is a probability distribution made up of all possible sample statistics computed from samples of the same size randomly drawn from the same population, along with their associated probabilities. | 
发表于 2009-1-9 10:50
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