Exam 7: Sampling and Sampling Distributions

The sampling distribution of has a mean equal to the square root of the population proportion p.

The sampling distribution of the sample means is close to the normal distribution only if the distribution of the population is close to normal.

According to the central limit theorem, for samples of size 169 drawn from a population with µ = 1,014 and σ = 65, the standard deviation of the sample means would equal ___.

The sampling distribution of is close to normal provided that n≥30.

According to the central limit theorem, if a sample of size 100 is drawn from a population with a standard deviation of 80, the standard deviation of sample means would equal ___.

Suppose a population has a mean of 90 and a standard deviation of 28.If a random sample of size 49 is drawn from the population, the probability of drawing a sample with a mean between 85 and 95 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.Albert instructs his staff to record the waiting times for the first 45 walk-in customers arriving after the noon hour.Albert's sample is a ___.

Suppose 90% of students in some specific college have a computer at home and a sample of 40 students is taken.The probability that more than 30 of those in the sample have a computer at home can be approximated using the normal approximation.

According to the central limit theorem, for samples of size 64 drawn from a population with µ = 800 and σ = 56, the mean 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?

With cluster sampling, there is homogeneity within a subgroup or stratum.

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.Albert randomly selects 4 as a starting point and instructs his staff to record the waiting times for the 4th walk-in customer and every 10th customer thereafter (4, 14, 24, etc.).Albert's sample is a ___.

If every 15^th item is systematically sampled to produce a same size of 90 items, the population has 1,350 items.

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 is

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.28% of clients are from the healthcare industry, 35% are manufacturing companies, 27% are financial firms, and 7% are construction companies.For this purpose, she gets random five-digits numbers from the website random.org (which offers true random numbers on the Internet).Then she uses these numbers to select 140 random clients from the healthcare sector, 175 from the manufacturing sector, 135 from the manufacturing sector, and 35 from the construction sector.This is an example of ______.

Suppose a population has a mean of 90 and a standard deviation of 28.If a random sample of size 49 is drawn from the population, the probability of drawing a sample with a mean of more than 95 is ___.

Suppose a population has a mean of 400 and a standard deviation of 24.If a random sample of size 144 is drawn from the population, the probability of drawing a sample with a mean less than 402 is ___.

The mean of the sample means is the same as the mean of the population

Suppose the population of all public Universities shows the annual parking fee per student is normally distributed with a mean of $110 with a standard deviation of $18.If a random sample of size 49 is drawn from the population, the probability of drawing a sample with a sample mean between $100 and $115 is _______.

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, 2000, 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 ___.