Exam 7: Sampling and Sampling Distributions

If the amount of gasoline purchased per car at a large service station has a population mean of 15 gallons and a population standard deviation of 4 gallons and it is assumed that the amount of gasoline purchased per car is symmetric, there is approximately a 68.26% chance that a random sample of 16 cars will have a sample mean between 14 and 16 gallons.

Coverage error can become an ethical issue if a particular group is intentionally excluded from the frame.

A study at a college on the west coast reveals that, historically, 45% of the students are minority students. If random samples of size 75 are selected, 95% of the samples will have more than ________% of minority students.

Which of the following sampling methods will more likely be susceptible to ethical violation?

A study at a college on the west coast reveals that, historically, 45% of the students are minority students. The expected percentage of minority students in their next group of freshmen is ________.

For a population frame containing N = 1,007 individuals, what code number should you assign to the first person on the list in order to use a table of random numbers?

TABLE 7-5 According to a survey, only 15% of customers who visited the web site of a major retail store made a purchase. Random samples of size 50 are selected. -Referring to Table 7-5, 90% of the samples will have more than what percentage of customers who will make a purchase after visiting the web site?

TABLE 7-1 The manager of the customer service division of a major consumer electronics company is interested in determining whether the customers who have purchased a DVD player made by the company over the past 12 months are satisfied with their products. -Referring to Table 7-1, if a customer survey questionnaire is included in all the DVD players made and sold by the company over the past 12 months, this method of collecting data will most like suffer from a

TABLE 7-5 According to a survey, only 15% of customers who visited the web site of a major retail store made a purchase. Random samples of size 50 are selected. -Referring to Table 7-5, 90% of the samples will have less than what percentage of customers who will make a purchase after visiting the web site?

A sample of size 25 provides a sample variance of 400. The standard error, in this case equal to 4, is best described as the estimate of the standard deviation of means calculated from samples of size 25.

A sample that does not provide a good representation of the population from which it was collected is referred to as a(n)________ sample.

The question: "Have you used any form of illicit drugs over the past two months?" will most likely result in measurement error if the question is answered.

The standard error of the sampling distribution of a sample proportion is , where p is the sample proportion

Which of the following is true about the sampling distribution of the sample mean?

TABLE 7-1 The manager of the customer service division of a major consumer electronics company is interested in determining whether the customers who have purchased a DVD player made by the company over the past 12 months are satisfied with their products. -Referring to Table 7-1, if there are four different brands of DVD players made by the company, the best sampling strategy would be to use a

The amount of time required for an oil and filter change on an automobile is normally distributed with a mean of 45 minutes and a standard deviation of 10 minutes. A random sample of 16 cars is selected. What is the probability that the sample mean will be between 45 and 52 minutes?

TABLE 7-6 According to an article, 19% of the entire population in a developing country have high-speed access to the Internet. Random samples of size 200 are selected from the country's population. -Referring to Table 7-6, among all the random samples of size 200, ________ % will have less than 20% who have high-speed access to the Internet.