Exam 7: Sampling

To check if the central limit theorem holds for a sample proportion (and therefore can be used for calculating confidence intervals),the value calculated from np(1-p)should be

To calculate the "optimal" sample size,all of the following information is needed except

Suppose a researcher is conducting a bivariate analysis with 5 categories for each variable in the cross-tabulation.Using the practical rule of thumb,what is the recommended minimum total sample size?

All of the following statements about convenience samples are true except

A _______________ is,loosely speaking,what researchers wish to make inferences about but for which researchers lack the resources (time,funds,energy)to conduct a full census.

Statistical theory,specifically the central limit theorem,tells us that we can be 68 percent certain that the true population mean lies within one standard error from the sample mean.

Although stratified sampling can be less costly and easier to conduct,it will almost always have a higher standard error of the estimator than a simple random sample.

All statistical tests,such as calculation of the mean and standard error of the sampling distribution can be calculated and are valid under the following condition(s):

All of the following methods of sampling require a complete and accurate list of the elements of the population except

Explain the two primary ways a researcher can be assured that each element in an area sample has an equal chance of being selected.

Although sampling errors tend to decrease with sample size,non-sampling errors tend to increase with sample size.

As the sample size increases,the confidence interval around a mean will also become larger.

All of the following statements are true of the required sample size,except that

What are absolute and relative precision?

Discuss the constraints that affect sample size decisions.

For finite populations,the formula used for calculating the standard error of the sampling distribution of the mean must be modified by the _______________.

Precision expressed in units is called relative precision.

Outline the fives steps in selecting a sample.

With non-probability sampling,each element of the population

The coefficient of variation is the ratio of the