Question 1

The area under the sampling distribution curve between any two points can be calculated in terms of r values.

Accepted Answer

The area under the sampling distribution curve is calculated using probabilities, not r values, which are correlation coefficients.

Question 2

According to the text,a parameter denotes the true value that would be obtained if a census,rather than a sample,were undertaken.

Accepted Answer

The text states that "a parameter is a numerical characteristic of a population, and it denotes the true value that would be obtained if a census, rather than a sample, were undertaken".

Question 3

The measures of central tendency for a normal distribution are all identical.

Accepted Answer

In a normal distribution, the mean, median, and mode are all identical and represent the center of the distribution.

Question 4

Statistical inference is the process of generalizing the sample results to the population results.

Accepted Answer

Statistical inference involves making conclusions about a larger population based on data collected from a smaller sample. Therefore, it is a process of generalizing the sample results to the population results.

Question 5

A statistic is a summary description of a characteristic or measure of the sample.

Accepted Answer

A statistic is a numerical measure calculated from a sample that summarizes a characteristic of the sample.

Question 6

The number of standard errors that a point is away from the mean is called the z value.

Accepted Answer

The number of standard errors that a point is away from the mean is called the z-score or standardized score.

Question 7

The error that results when the particular sample selected is an imperfect representation of the population of interest is called nonrandom sampling error.

Accepted Answer

The error described is known as "sampling error," not "nonrandom sampling error." Sampling error occurs due to the natural variability in selecting a sample from a population.

Question 8

A summary description of a fixed characteristic or measure of the target population is called a standard deviation.

Accepted Answer

A standard deviation is a measure of variability or spread of a set of data, not a summary description of a fixed characteristic or measure of the target population.

Question 9

The standard deviation of the sampling distribution of the mean or proportion is called random error.

Accepted Answer

The standard deviation of the sampling distribution of the mean or proportion is referred to as standard error, not random error. Random error refers to the natural variability that occurs in measurements, such as due to chance or measurement error.

Question 10

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

Accepted Answer

The range into which the true population parameter will fall, assuming a given level of confidence, is called the confidence interval, not the sampling distribution. The sampling distribution refers to the distribution of sample statistics (such as means or proportions) that would be obtained from repeated sampling from the same population.

Question 11

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

Accepted Answer

This is true. Statistical inference is the process of using sample data to make generalizations about a population.

Question 12

Confidence intervals around sample means or proportions are estimated using the variance formula.

Accepted Answer

Confidence intervals are estimated using the standard error, which is derived from the variance formula, but not the variance itself.

Question 13

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

Accepted Answer

This is the definition of a sampling distribution.

Question 14

When estimating a population parameter by using a sample statistic,the precision level is the desired size of the estimating interval.

Accepted Answer

The precision level refers to the level of accuracy or the desired size of the estimating interval. So, the statement is true.

Question 15

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

Accepted Answer

This statement is true. By understanding the sampling distribution of a statistic, such as the mean or standard deviation, we can calculate the probability of observing certain values and use this information to make inferences about the population values.

Question 16

A normal distribution is a basis for classical statistical inference that is bell-shaped and symmetrical in appearance.

Accepted Answer

A normal distribution is indeed bell-shaped and symmetrical in appearance, and it is a foundation for classical statistical inference.

Question 17

The sample statistic is used as an estimate of the population parameter.

Accepted Answer

This is true. When the population is too large, it is not practical to measure each individual unit. In such cases, we take a random sample from the population and conduct statistical analysis on the sample to estimate the population parameter. The value obtained from the sample is called the sample statistic, which serves as an estimate of the population parameter.

Question 18

Standard deviation is the maximum permissible difference between the sample statistic and the population parameter.

Accepted Answer

Standard deviation measures the amount of variability or dispersion in a set of data. It is not a measure of the permissible difference between a sample statistic and a population parameter. The standard error of the estimator is the measure of the variability of the sample statistic.

Question 19

According to the text,the confidence level is the probability that a confidence interval will include the population parameter.

Accepted Answer

According to the definition of confidence level, it is the probability that a confidence interval will contain the true population parameter. Therefore, statement A is true.

Question 20

According to the text,the sampling distribution of the means is a normal distribution.

Accepted Answer

The central limit theorem states that if a sample is large enough (typically n ≥ 30), the sampling distribution of the sample means will be approximately normally distributed.

Quiz 13: Sampling: Final and Initial Sample Size Determination