Exam 7: Sampling and Sampling Distributions

TABLE 7-5 According to a survey,only 15% of customers who visited the website of a major retail store made a purchase.Random samples of size 50 are selected. -Referring to Table 7-5,the standard deviation of all the sample proportions of customers who will make a purchase after visiting the website is ________.

If a simple random sample is chosen with replacement,each individual has the same chance of selection on every selection.

TABLE 7-3 The mean selling price of new homes in a small town over a year was $115,000.The population standard deviation was $25,000.A random sample of 100 new home sales from this city was taken. -Referring to Table 7-3,what is the probability that the sample mean selling price was between $114,000 and $116,000?

Suppose μ = 50 and σ = 10 for a population.In a sample where n = 100 is randomly taken,90% of all possible sample means will fall between 49 and 51.

TABLE 7-5 According to a survey,only 15% of customers who visited the website of a major retail store made a purchase.Random samples of size 50 are selected. -Referring to Table 7-5,what proportion of the samples will have between 20% and 30% of customers who will make a purchase after visiting the website?

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.Which of the following will be a good frame for drawing a sample?

Major league baseball salaries averaged $3.26 million with a standard deviation of $1.2 million in a recent year.Suppose a sample of 100 major league players was taken.Find the approximate probability that the mean salary of the 100 players was less than $2.5 million.

Which of the following yields a simple random sample?

If the expected value of a sample statistic is equal to the parameter it is estimating,then we call that sample statistic

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

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 ________.

Which of the following statements about the sampling distribution of the sample mean is incorrect?

The amount of bleach a machine pours into bottles has a mean of 36 oz.with a standard deviation of 0.15 oz.Suppose we take a random sample of 36 bottles filled by this machine.The probability that the mean of the sample is between 35.95 and 35.98 oz.is ________.

Systematic samples are less efficient than a stratified sample.

Which of the following yields a systematic sample?

The only reliable way a researcher can make statistical inferences from a sample to a population is to use nonprobability sampling methods.

For distributions such as the normal distribution,the arithmetic mean is considered more stable from sample to sample than other measures of central tendency.

TABLE 7-5 According to a survey,only 15% of customers who visited the website of a major retail store made a purchase.Random samples of size 50 are selected. -A study at a college in 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 sample size 1,the sampling distribution of the mean will be normally distributed

The sampling process begins by locating appropriate data sources called ________.