Exam 7: Sampling and Sampling Distributions

We can randomly select a sample from an infinite population of potential process measurements by sampling the process at different and equally spaced time points.

A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as _______________.

A manufacturing company measures the weight of boxes before shipping them to the customers.If the box weights have a population mean and standard deviation of 90 lbs.and 24 lbs. ,respectively,then based on a sample size of 36 boxes,what is the probability that the average weight of the boxes will exceed 94 lbs.?

The notation for the standard deviation of the sampling distribution of the sample mean is __________.

A PGA (Professional Golf Association)tournament organizer is attempting to determine whether hole (pin)placement has a significant impact on the average number of strokes for the 13^th hole on a given golf course.Historically,the pin has been placed in the front right corner of the green,and the historical mean number of strokes for the hole has been 4.25,with a standard deviation of 1.6 strokes.On a particular day during the most recent golf tournament,the organizer placed the hole (pin)in the back left corner of the green.64 golfers played the hole with the new placement on that day.Determine the probability of the sample average number of strokes exceeding 4.75.

Find ?_x,if ? = 400, $\mathrm { P } ( \bar { X } < 396 ) = .0228$ And n = 100.

Find $\mathrm { P } ( \bar { X } < 35 )$ If ? = 40,?_x = 16,n = 16.

The population of all _________________ proportions is described by the sampling distribution of $\hat { p }$ .

A "Yes or No" question is _____________.

The internal auditing staff of a local manufacturing company performs a sample audit each quarter to estimate the proportion of accounts that are more than 90 days overdue (delinquent).The historical records of the company show that over the past 8 years,the average has been that 14 percent of the accounts have been delinquent.For this quarter,the auditing staff randomly selected 250 customer accounts.What is the probability that at least 30 accounts will be classified as delinquent?

A common practice in selecting a sample from a large geographic area is multistage cluster sampling.

The target population is the result of sampling from the original population that is of interest to the researcher.

According to a hospital administrator,historical records over the past 10 years have shown that 20 percent of the major surgery patients are dissatisfied with after-surgery care in the hospital.A scientific poll based on 400 hospital patients has just been conducted.What is the probability that fewer than 64 patients will not be satisfied with the after-surgery care?

The diameter of small Nerf balls manufactured at a factory in China is expected to be approximately normally distributed with a mean of 5.2 inches and a standard deviation of .08 inches.Suppose a random sample of 20 balls is selected.Find the interval that contains 95.44 percent of the sample means.

If a population is known to be normally distributed,then it follows that the sample standard deviation must equal σ.

For large samples,the sampling distribution of $\bar { X }$ Is approximately normal with a mean of _____.

A random sample of size 36 is taken from a population with mean 50 and standard deviation 5.What is $\sigma _ { \bar { X }}$ ?

If we wish to estimate a population parameter by using a sample statistic,we are using ___________.

For nonnormal populations,as the sample size (n)___________________,the distribution of sample means approaches a(n)________________ distribution.

__________ sampling is defined as sampling where we know the chance that each element in the population will be included in the sample.