Exam 7: Sampling and Sampling Distributions

A population frame for a survey contains a listing of 6,179 names. Using a table of random numbers, which of the following code numbers will appear on your list?

Assume that house prices in a neighborhood are normally distributed with a standard deviation of $20,000. A random sample of 16 observations is taken. What is the probability that the sample mean differs from the population mean by more than $5,000?

To gather information on the preferences of instructors at universities on topics for a business statistics textbook that it will publish, a publishing company invited 10 faculty members who have adopted one of the textbooks that it has published. This is an example of a

Sampling error can be completely eliminated by taking larger sample sizes.

A manufacturer of power tools claims that the mean amount of time required to assemble their top-of-the-line table saw is 80 minutes with a standard deviation of 40 minutes. Suppose a random sample of 64 purchasers of this table saw is taken. The probability that the sample mean will be less than 82 minutes is ________.

The owner of a fish market has an assistant who has determined that the weights of catfish are normally distributed, with mean of 3.2 pounds and standard deviation of 0.8 pound. If a sample of 16 fish is taken, what would the standard error of the mean weight equal?

To demonstrate a sampling method, the instructor in a class picked the first five students sitting in the last row of the class. This is an example of a

Measurement error can become an ethical issue when an interviewer purposely guides the responses in a particular direction.

The owner of a fish market has an assistant who has determined that the weights of catfish are normally distributed, with mean of 3.2 pounds and standard deviation of 0.8 pound. If a sample of 64 fish yields a mean of 3.4 pounds, what is probability of obtaining a sample mean this large or larger?

The mean of the sampling distribution of a sample proportion is the population proportion, π.

The standard error of the mean is also known as the standard deviation of the sampling distribution of the sample mean.

TABLE 7-4 The lifetimes of a certain brand of light bulbs are known to be normally distributed with a mean of 1,600 hours and a standard deviation of 400 hours. A random sample of 64 of these light bulbs is taken. -Referring to Table 7-4, the probability is 0.20 that the sample mean lifetime differs from the population mean lifetime by at least how many hours?

The standard error of the mean for a sample of 100 is 30. In order to cut the standard error of the mean to 15, we would

If the population distribution is unknown, in most cases the sampling distribution of the mean can be approximated by the normal distribution if the samples contain at least 30 observations.

TABLE 7-7 Online customer service is a key element to successful online retailing. According to a marketing survey, 37.5% of online customers take advantage of the online customer service. Random samples of 200 customers are selected. -Referring to Table 7-7, ________% of the samples are likely to have between 35% and 40% who take advantage of online customer service.

A sampling distribution is a distribution for a statistic.

The sample mean is an unbiased estimate of the population mean.

To estimate the mean number of hours a student at a major university spent in the library, a researcher obtained the list of students from the registrar's office, from which she can select a random sample 200 students. This list is a ________.

TABLE 7-7 Online customer service is a key element to successful online retailing. According to a marketing survey, 37.5% of online customers take advantage of the online customer service. Random samples of 200 customers are selected. -Referring to Table 7-7, the population mean of all possible sample proportions is ________.

For sample size 16, the sampling distribution of the mean will be approximately normally distributed