Question 1

The z value for a point is the number of standard deviations a point is away from the mean.

Accepted Answer

False

Question 2

The sampling distribution is the probability of the values of a sampling statistic computed for each possible sample that could be drawn from the target population under a specified sampling plan.

Accepted Answer

False

Question 3

The confidence interval approach to sample size determination is based on the construction of confidence intervals around the means or proportions using the standardized variate formula.

Accepted Answer

False

Question 4

Survey System (www.surveysystem.com)and the Discovery Research Group (www.drgutah.com)are Web sites on the Internet that offer free use of sample size and/or confidence interval calculators.

Accepted Answer

Both websites offer free use of sample size and/or confidence interval calculators.

Question 5

In the statistical approach to determining sample size,the precision level is specified in the end.

Accepted Answer

In the statistical approach to determining sample size, the precision level (also known as the margin of error) is specified at the beginning of the study design process, not at the end. This helps in determining the required sample size to achieve the desired precision for the study's estimates.

Question 6

Assuming no measurement error,the reliability of an estimate of a population parameter can be assessed in terms of its standard error.

Accepted Answer

The standard error reflects the precision of an estimate and a smaller standard error indicates greater reliability. Therefore, assuming no measurement error, the reliability of an estimate of a population parameter can be assessed in terms of its standard error.

Question 7

The statistical approach to determining sample size is based on the construction of confidence intervals around sample means or proportions.

Accepted Answer

The statistical approach to determining sample size involves calculating the margin of error and confidence interval around sample means or proportions, which requires knowledge of the desired level of precision and the amount of variability in the population.

Question 8

When using the confidence interval approach to sample size determination,if the statistic of interest is a proportion,rather than a mean,the approach to sample size determination is very different.

Accepted Answer

The approach to sample size determination for a proportion involves a similar conceptual framework as for a mean, using a formula that accounts for the desired confidence level, the variability in the population (estimated by the proportion in the case of categorical data), and the margin of error. The formulas differ in their specifics (e.g., using the standard deviation for means vs. the standard error for proportions) but the underlying principles of determining how large a sample is needed to estimate the parameter of interest with a certain level of confidence and precision are consistent across both types of statistics.

Question 9

If the researcher is required to estimate several parameters,not just one,the calculation of sample size in these cases should be based on a consideration of all the parameters that must be estimated.

Accepted Answer

When estimating multiple parameters, sample size calculation should consider all of the parameters that need to be estimated. This ensures that the sample size is large enough to provide accurate estimates for all of the parameters of interest.

Question 10

The process of generalizing the sample results to the population results is called statistical inference.

Accepted Answer

This is correct. Statistical inference involves using sample results to make conclusions or predictions about a larger population.

Question 11

The confidence level is the range into which the true population parameter will fall,assuming a given level of confidence.

Accepted Answer

The confidence level represents the probability that the confidence interval contains the true population parameter, not the range itself. The confidence interval is the actual range estimate.

Question 12

When using the confidence interval approach to sample size determination,in some cases,precision is specified in relative rather than absolute terms.In other words,it may be specified that the estimate be within plus or minus R percentage points of the mean.

Accepted Answer

This statement is true. When using the confidence interval approach, precision can be specified in relative terms, such as within plus or minus 5% of the mean. This is called the margin of error and is based on the sample size and the desired level of confidence.

Question 13

The concept of a sampling distribution enables us to use probability theory to make inferences about the population values.

Accepted Answer

The concept of a sampling distribution allows us to infer population values based on the characteristics of the sample distribution, using probability theory.

Question 14

When the sample size is 10 percent or more of the population size,the standard error formulas will overestimate the standard deviation of the population mean or proportion.Hence,these should be adjusted by a finite population correction factor.

Accepted Answer

This is true. When the sample size is 10 percent or more of the population size, the standard error formulas will overestimate the standard deviation of the population mean or proportion. This is because the sample is becoming a larger proportion of the population and therefore, does not accurately represent the variability of the larger population. To adjust for this, a finite population correction factor should be applied.

Question 15

The statistically determined sample size is the net or final sample size the sample remaining after eliminating potential respondents who do not qualify or who do not complete the interview.

Accepted Answer

The statement is true. The statistically determined sample size is the initial sample size calculated based on the desired level of precision, confidence level, and variability in the population. However, the final sample size may differ from the calculated sample size due to non-response, incomplete responses, or exclusion of respondents who do not meet the eligibility criteria. The net or final sample size is the actual sample size used in the analysis.

Question 16

Specify the level of confidence is the first step in the confidence interval approach to determining sample size.

Accepted Answer

The answer of Specify the level of confidence is the...

Question 17

When determining the sample size,if the population standard deviation,s,is unknown and an estimate is used,the standard deviation should be re-estimated once the sample has been drawn.Next a revised confidence interval should be calculated to determine the precision level actually obtained.

Accepted Answer

The answer of When determining the sample size,if the population...

Question 18

The confidence level is the probability that a confidence interval will include the population parameter.

Accepted Answer

The confidence level represents the degree of certainty or probability that the confidence interval (estimation interval) includes the true population parameter.

Question 19

The sampling distribution of the mean is a binomial distribution.

Accepted Answer

The sampling distribution of the mean is a normal distribution, not a binomial distribution.

Question 20

Two major nonresponse issues in sampling are improving response rates and adjusting for nonresponse.

Accepted Answer

Improving response rates and adjusting for nonresponse are indeed two major nonresponse issues in sampling.

Quiz 12: Sampling: Final and Initial Sample Size Determination

The z value for a point is the number of standard deviations a point is away from the mean.

The sampling distribution is the probability of the values of a sampling statistic computed for each possible sample that could be drawn from the target population under a specified sampling plan.

The confidence interval approach to sample size determination is based on the construction of confidence intervals around the means or proportions using the standardized variate formula.

Survey System (www.surveysystem.com)and the Discovery Research Group (www.drgutah.com)are Web sites on the Internet that offer free use of sample size and/or confidence interval calculators.

In the statistical approach to determining sample size,the precision level is specified in the end.

Assuming no measurement error,the reliability of an estimate of a population parameter can be assessed in terms of its standard error.

The statistical approach to determining sample size is based on the construction of confidence intervals around sample means or proportions.

When using the confidence interval approach to sample size determination,if the statistic of interest is a proportion,rather than a mean,the approach to sample size determination is very different.

If the researcher is required to estimate several parameters,not just one,the calculation of sample size in these cases should be based on a consideration of all the parameters that must be estimated.

The process of generalizing the sample results to the population results is called statistical inference.

The confidence level is the range into which the true population parameter will fall,assuming a given level of confidence.

When using the confidence interval approach to sample size determination,in some cases,precision is specified in relative rather than absolute terms.In other words,it may be specified that the estimate be within plus or minus R percentage points of the mean.

The concept of a sampling distribution enables us to use probability theory to make inferences about the population values.

When the sample size is 10 percent or more of the population size,the standard error formulas will overestimate the standard deviation of the population mean or proportion.Hence,these should be adjusted by a finite population correction factor.

The statistically determined sample size is the net or final sample size the sample remaining after eliminating potential respondents who do not qualify or who do not complete the interview.

Specify the level of confidence is the first step in the confidence interval approach to determining sample size.

When determining the sample size,if the population standard deviation,s,is unknown and an estimate is used,the standard deviation should be re-estimated once the sample has been drawn.Next a revised confidence interval should be calculated to determine the precision level actually obtained.

The confidence level is the probability that a confidence interval will include the population parameter.

The sampling distribution of the mean is a binomial distribution.

Two major nonresponse issues in sampling are improving response rates and adjusting for nonresponse.