Question 1

The range of the measurement is the largest measurement plus the smallest measurement.

Accepted Answer

The range is the largest minus the smallest measurement.

Question 2

The population mean is the average of the population measurements.

Accepted Answer

This mean is calculated by adding all of the population measurements and dividing the resulting sum by the number of population measurements.

Question 3

It is appropriate to use the Empirical Rule to describe a population that is extremely skewed.

Accepted Answer

The Empirical Rule should be used for normally distributed populations.

Question 4

The line that minimizes the sum of the squared horizontal (x) distances between the points on the scatter plot and the line is the least squares line.

Accepted Answer

The definition of the least squares line is the line that minimizes the sum of the squared vertical distances (y) between the points.

Question 5

The population mean is the point estimate of the sample mean.

Accepted Answer

The sample mean is the point estimate of the population mean.

Question 6

If there are seven classes in a frequency distribution, then the fourth class will always contain the median.

Accepted Answer

The median is the middle measurement of the data set. Depending on the shape of the distribution, the median can be in any of the classes.

Question 7

Chebyshev's Theorem is only of practical use when analyzing a non-mound-shaped population that is not very skewed.

Accepted Answer

This theorem gives large intervals containing reasonably large fractions of the population units no matter what the population's shape might be.

Question 8

Range is a better measure of variation than standard deviation.

Accepted Answer

The standard deviation is a better measure of variability than range.

Question 9

The median is said to be resistant to extreme values.

Accepted Answer

This is because the median divides the population or sample into two roughly equal parts.

Question 10

Z-score is often used as a measure of risk.

Accepted Answer

Z-score is used to measure a measurement's distance from the mean.

Question 11

The median is the value below which and above which approximately 50 percent of the measurements lie.

Accepted Answer

It is the central tendency of a population and evenly splits the population or sample into two.

Question 12

A correlation coefficient close to −1 says x and y are highly related.

Accepted Answer

This means they have a strong tendency to move together in a straight-line fashion.

Question 13

Data summarized in a frequency distribution or histogram form are often called weighted data.

Accepted Answer

Data summarized in a frequency distribution or histogram form are called grouped data.

Question 14

The weights that are used in calculating a weighted mean will vary depending on the situation.

Accepted Answer

The idea is to choose weights that represent the relative importance of the measurements in the population or sample.

Question 15

In a symmetric population, the median equals the mode.

Accepted Answer

The population is a perfect bell curve.

Question 16

The population variance is the average of the squared deviations of the individual population measurements from the population mean.

Accepted Answer

This population variance is represented by sigma squared.

Question 17

The pth percentile is a value such that (100 − p) percent of the measurements fall at or below the value.

Accepted Answer

The pth percentile is a value such that p percent of the measurements fall at or below the value.

Question 18

The median is the measure of central tendency that divides a population or sample into four equal parts.

Accepted Answer

The median divides a population into two equal parts.

Question 19

The mean is one component of the five-number summary.

Accepted Answer

The five-number summary includes Q1, Q2, Q3, and the smallest and largest measurements.

Question 20

The mode is the measurement in a sample or population that occurs most frequently.

Accepted Answer

This is the measurement that occurs at the highest frequency.

Quiz 3: Descriptive Statistics and Analytics: Numerical Methods