Exam 7: Sampling and Sampling Distributions

According to the central limit theorem, for samples of size 64 drawn from a population with μ = 800 and σ = 56, the standard deviation of the sampling distribution of sample means would equal _______.

Alice Zhong is the VP of Operations at Pearl Financial Services.She wants to measure customer satisfaction after a new website and other changes were introduced a few months ago.For this purpose, she instructs her staff to prepare a questionnaire and send it to any IP address that accesses the company's website from 8 a.m.to 9 a.m.during each day of the next four weeks.This is an example of ______.

Financial analyst Larry Potts needs a sample of 100 securities listed on either the New York Stock Exchange (NYSE)or the American Stock Exchange (AMEX).According to the Wall Street Journal's "Stock Market Data Bank," 2,531 NYSE securities and 746 AMEX securities were traded on the previous business day.Larry directs his staff to randomly select 77 NYSE and 23 AMEX securities.His sample is a ____________.

Suppose 65% of all college students have a laptop computer at home and a sample of 150 is taken.The standard deviation of the sampling distribution of $\hat { p }$ is

Suppose a population has a mean of 870 and a variance of 1,600.If a random sample of size 64 is drawn from the population, the probability that the sample mean is between 860 and 875 is closest to _______.

Pinky Bauer, Chief Financial Officer of Harrison Haulers, Inc., suspects irregularities in the payroll system.She knows that 2,500 payroll vouchers have been issued since January 1, 2018, and her staff doesn't have time to inspect each voucher.So, she orders her staff to inspect the last 200 vouchers.Her sample is a ___________.

Alice Zhong is the VP of Operations at Pearl Financial Services.She wants to measure customer satisfaction after a new website and other changes were introduced a few months ago.For this purpose, she uses random five-digits numbers from the website random.org (which offers true random numbers on the Internet).This is an example of ______.

Saving time and money are reasons to take a sample rather than do a census.

Suppose 65% of all college students have a laptop computer at home and a sample of 150 students is taken.The mean of the sampling distribution of $\hat { p }$ is

Albert Abbasi, VP of Operations at Ingleside International Bank, is evaluating the service level provided to walk-in customers.Accordingly, he plans a sample of waiting times for walk-in customers.If the population of waiting times has a mean of 15 minutes and a standard deviation of 4 minutes, the probability that Albert's sample of 64 will have a mean less than 15 minutes is ________.

Catherine Chao, Director of Marketing Research, needs a sample of Kansas City households to participate in the testing of a new toothpaste package.If 40% of the households in Kansas City prefer the new package, the probability that Catherine's random sample of 300 households will have a sample proportion greater than 0.45 is closest to ___________.

According to the central limit theorem, if a sample of size 56 is drawn from a population with a standard deviation of 14, the standard deviation of the distribution of the sample means would equal _______.

In Norway, approximately 22% of vehicles are electric vehicles.Which is closest to the probability of randomly selecting 250 cars and finding out that 60 or more are electric?

Paige DeMarco is the Vice President for University Advancement at State University.She is responsible for the capital campaign to raise money for the new student services building.Paige plans to target alumni and acquires her sampling frame from the State University Office of Alumni Relations.She intends to contact these individuals regarding possible donations.Paige chooses her sample by selecting six-digit numbers (1 to 150,000)from a random number table.Her sample is a _________.

Decreasing the sample size causes the sampling distribution of x̄ to ________.

Suppose 40% of all college students have a computer at home and a sample of 100 is taken.Which is closest to the probability that more than 50 of those in the sample have a computer at home?

In a random sampling technique, every unit of the population has a randomly varying chance or probability of being included in the sample.

Suppose 30% of the U.S.population has green eyes.If a random sample of size 1200 U.S.citizens is drawn, then the probability that less than 348 of those U.S.citizens have green eyes is closest to _______.

A carload of various palletized aluminum castings has arrived at Mansfield Motor Manufacturers.The car contains 1,000 pallets of 100 castings each.Mario Munoz, Manager of Quality Assurance, directs the receiving crew to deliver the 127th and 869th pallets to his crew for 100% inspection.Mario randomly selected 127 and 869 from a table of random numbers.Mario's sample of 200 castings is a _____________.

If every unit of the population has the same probability of being selected for the sample, then the researcher is probably conducting random sampling.