Quantitative Methods 【Reading 7】Sample example, assigned, performing, best

jawz

Fifty mutual funds are ranked according to performance. The five best performing funds are assigned the number 1, while the five worst performing funds are assigned the number 10. This is an example of a(n):

A) ordinal scale.

B) interval scale.

C) nominal scale.

---

The ordinal scale of measurement categorizes and orders data with respect to some characteristic. In this example, the ordinal scale tells us that a fund ranked “1” performed better than a fund ranked “10,” but it does not tell us anything about the difference in performance.

jawz

Which measure of scale has a true zero point as the origin?

A) Nominal scale.

B) Ordinal scale.

C) Ratio scale.

---

Ratio scales are the strongest level of measurement; they quantify differences in the size of data and have a true zero point as the origin.

jawz

Which of the following statements regarding the terms population and sample is least accurate?

A) A sample includes all members of a specified group.

B) A sample's characteristics are attributed to the population as a whole.

C) A descriptive measure of a sample is called a statistic.

---

A population includes all members of a specified group. A sample is a portion, or subset of the population of interest.

jawz

Which of the following statements about statistical concepts is least accurate?

A) A frequency distribution is a tabular display of data summarized into a relatively small number of intervals.

B) A sample contains all members of a specified group, but a population contains only a subset.

C) A parameter is any descriptive measure of a population characteristic.

---

A population is defined as all members of a specified group, but a sample is a subset of a population.

jawz

A summary measure that is computed to describe a population characteristic from a sample is called a:

A) census.

B) parameter.

C) statistic.

---

When sampling from a portion of the population, you compute a statistic to make inferences about the population.

jawz

Which one of the following alternatives best describes the primary use of inferential statistics? Inferential statistics are used to:

A) summarize the important characteristics of a large data set based on statistical characteristics of a smaller sample.

B) make forecasts, estimates or judgments about a large set of data based on statistical characteristics of a smaller sample.

C) make forecasts based on large data sets.

---

Inferential statistics are used mainly to make forecasts, estimates or judgements about a large set of data based on statistical characteristics of a smaller set of data.

jawz

Which one of the following alternatives best describes the primary use of descriptive statistics? Descriptive statistics are used to:

A) obtain data about the characteristics of any data set that can be used to assess the likelihood of the occurrence of future events.

B) arrive at estimates regarding a large set of data regarding the statistical characteristics of a smaller sample.

C) summarize important characteristics of large data sets.

---

Descriptive statistics are used mainly to summarize important characteristics of large data sets.

jawz

What is the main difference between descriptive statistics and inferential statistics? Descriptive statistics are:

A) used to summarize data while inferential statistics are used to obtain precise information about a large data set.

B) used to make forecasts about the likelihood of upcoming events while inferential statistics are used to summarize any data set.

C) used to summarize a large data set while inferential statistics involves procedures used to make forecasts or judgments about a large data set by examining a smaller sample.

---

Descriptive statistics are used to summarize a large data set while inferential statistics are based on procedures used to make forecasts or judgments about a large data set by examining a smaller set of data.

jawz

Which of the following statements regarding various statistical measures is least accurate?

A) The correlation coefficient is calculated by dividing the covariance of two random variables by the product of their standard deviations.

B) Variance equals the sum of the squared deviations from the mean times the probability that that each outcome will occur.

C) The coefficient of variation is calculated by dividing the mean by the standard deviation.

---

The coefficient of variation equals the standard deviation divided by the mean.

jawz

Which of the following is an example of a parameter?

A) Population variance.

B) Sample standard deviation.

C) Sample mean.

---

A parameter is any descriptive measure of a population characteristic. The population variance describes a population while the sample standard deviation and sample mean are each descriptive measures of samples.