Question 1

What is one advantage of the interquartile range (Q) over the range (R)?

Accepted Answer

A)  Q ignores the first and third quartiles. 
B)  Q can be used for nominal-level variables. 
C)  Q is based on only the middle 50% of the scores. 
D)  Q includes the most extreme scores.

Question 2

Which of these terms is the preferred measure of central tendency for the variable income distribution, which almost always has a positive skew?

Accepted Answer

A)  range 
B)  median 
C)  mode 
D)  mean

Question 3

Which of these variables would be most appropriate for calculating the interquartile range?

Accepted Answer

A)  very happy, somewhat happy, somewhat unhappy, very unhappy 
B)  left handed, right-handed, ambidextrous 
C)  political party preference 
D)  language preference: English, French, other

Question 4

Table 3.3 Means and Standard Deviations in Monthly Accident Events for Two Mining Companies, 2014-2018
 
-Refer to Table 3.3. Which of the following could we conclude from these data?

Accepted Answer

A)  Jackson Minerals started off with many accidents, but it is improving. 
B)  H & W Energy Resources had fewer accidents on average than Jackson Minerals, but it also had more month-to-month variation. 
C)  H & W Energy Resources had fewer accidents from 2014 to 2018, and varied less from one month to the next than Jackson Minerals. 
D)  Jackson Minerals had only about 1/3 as many accidents as H & W Energy Resources, but it had more month-to-month variation.Had more

Question 5

Which of the following always happens when the mean is subtracted from a set of numbers, and all the differences are summed?

Accepted Answer

A)  The sum is 0. 
B)  The sum is 1. 
C)  The sum is equal to the mean. 
D)  The sum is equal to the variance.

Question 6

What is the purpose of the expression ?(Xi)?

Accepted Answer

A)  to direct the researcher to find the middle score 
B)  to direct the researcher to find the average of the scores 
C)  to direct the researcher to find the median of the scores 
D)  to direct the researcher to find the sum of the scores

Question 7

What is the purpose of measures of central tendency?

Accepted Answer

A)  to find the most typical value of a distribution of scores 
B)  to find the most surprising value of a distribution of scores 
C)  to find the most significant value of a distribution of scores 
D)  to find the most important value of a distribution of scores

Question 8

According to the text, why is the mode sometimes not a good representation of the typical score in a distribution?

Accepted Answer

A)  Ordinal and interval-ratio variables lack a mode. 
B)  The mode is sometimes different from the majority of other scores in the distribution. 
C)  The mode is sometimes equal to the value of the dispersion. 
D)  The mode tells us how much cases tend to differ from the middle value rather than reflecting what is most common.

Question 9

Table 3.1 Data Set of Six Volunteers at a Charitable Organization
 
-Refer to Table 3.1. What is the mode of employment status?

Accepted Answer

A)  student 
B)  part-time worker 
C)  full-time worker 
D)  There is no mode for this distribution.

Question 10

On a survey, age was divided into three categories: younger than 18 years, 18 to 21 years, and older than 21 years. The researcher computed the mean age of the respondents by adding up the scores and then dividing by the number of cases. Why was this a mistake?

Accepted Answer

A)  because the data are interval-ratio and should not be treated as ordinal 
B)  because the data are only nominal and should not be treated as ordinal 
C)  because the data are continuous and should not be treated as discrete 
D)  because the data are ordinal and should not be treated as interval-ratio data

Question 11

The distribution of student test scores is severely left skewed. What would this mean?

Accepted Answer

A)  that the mean of the distribution is less than the median 
B)  that the mode of the distribution is less than the median 
C)  that the median of the distribution is less than the mean 
D)  that the mode of the distribution is less than the mean

Question 12

An army recruit scored in the 80th percentile of incoming soldiers for a fitness test. What can we conclude about that soldier?

Accepted Answer

A)  The soldier scored higher than 80% of soldiers taking the test. 
B)  The soldier scored higher than 20% of solders taking the test. 
C)  The soldier scored 30 points higher on the test than the average soldier. 
D)  No matter how many soldiers took the test, the soldier beat 20 of them on it.

Question 13

Researchers wish to compare the dispersion of student grades across eight universities of varying sizes. What strategy would allow them to properly compare grade dispersion across the eight distributions?

Accepted Answer

A)  adding up the deviations for the smallest and the largest university 
B)  dividing the squared deviations by the number of cases (N) for each university 
C)  calculating the mode for each of the eight universities 
D)  calculating the median for each of the eight universities

Question 14

Which set of scores shows the greatest level of dispersion?

Accepted Answer

A)  300, 310, 320 
B)  255, 250, 244 
C)  175.20, 164.50, 188.30 
D)  2, 80, 99

Question 15

Suppose a distribution has an outlying value far smaller than the other values in the distribution. What will happen to the standard deviation if the outlier is removed?

Accepted Answer

A)  It will necessarily diminish. 
B)  It will not change. 
C)  It will necessarily increase. 
D)  It is impossible to say without knowing the actual values in the distribution.

Question 16

Which of these statements describes the "least squares" principle?

Accepted Answer

A)  The mean is the point in a distribution around which the variation of the scores is minimized. 
B)  The range of an interval-ratio-level variable can never exceed the value of its mean. 
C)  The interquartile range will always contain a variable's median, but not necessarily the variable's mean. 
D)  Taking the square root of a variable's mean will create a more symmetrical distribution.

Question 17

What value is equal to the median?

Accepted Answer

A)  It is impossible to tell without knowing the actual scores in the distribution. 
B)  the first quartile 
C)  the second percentile 
D)  the fiftieth percentile

Question 18

What is the difference between central tendency and dispersion in a distribution of data?

Accepted Answer

The answer of What is the difference between central tendency...

Exam 3: Measures of Central Tendency and Dispersion

What is one advantage of the interquartile range (Q) over the range (R) ?

Which of these terms is the preferred measure of central tendency for the variable income distribution, which almost always has a positive skew?

Which of these variables would be most appropriate for calculating the interquartile range?

Table 3.3 Means and Standard Deviations in Monthly Accident Events for Two Mining Companies, 2014-2018 -Refer to Table 3.3. Which of the following could we conclude from these data?

Which of the following always happens when the mean is subtracted from a set of numbers, and all the differences are summed?

What is the purpose of the expression ?(X_i) ?

What is the purpose of measures of central tendency?

According to the text, why is the mode sometimes not a good representation of the typical score in a distribution?

Table 3.1 Data Set of Six Volunteers at a Charitable Organization -Refer to Table 3.1. What is the mode of employment status?

On a survey, age was divided into three categories: younger than 18 years, 18 to 21 years, and older than 21 years. The researcher computed the mean age of the respondents by adding up the scores and then dividing by the number of cases. Why was this a mistake?

The distribution of student test scores is severely left skewed. What would this mean?

An army recruit scored in the 80th percentile of incoming soldiers for a fitness test. What can we conclude about that soldier?

Researchers wish to compare the dispersion of student grades across eight universities of varying sizes. What strategy would allow them to properly compare grade dispersion across the eight distributions?

Which set of scores shows the greatest level of dispersion?

Suppose a distribution has an outlying value far smaller than the other values in the distribution. What will happen to the standard deviation if the outlier is removed?

Which of these statements describes the "least squares" principle?

What value is equal to the median?

What is the difference between central tendency and dispersion in a distribution of data?

Exam 3: Measures of Central Tendency and Dispersion

What is one advantage of the interquartile range (Q) over the range (R) ?

Which of these terms is the preferred measure of central tendency for the variable income distribution, which almost always has a positive skew?

Which of these variables would be most appropriate for calculating the interquartile range?

Table 3.3 Means and Standard Deviations in Monthly Accident Events for Two Mining Companies, 2014-2018 -Refer to Table 3.3. Which of the following could we conclude from these data?

Which of the following always happens when the mean is subtracted from a set of numbers, and all the differences are summed?

What is the purpose of the expression ?(Xi) ?

What is the purpose of measures of central tendency?

According to the text, why is the mode sometimes not a good representation of the typical score in a distribution?

Table 3.1 Data Set of Six Volunteers at a Charitable Organization -Refer to Table 3.1. What is the mode of employment status?

On a survey, age was divided into three categories: younger than 18 years, 18 to 21 years, and older than 21 years. The researcher computed the mean age of the respondents by adding up the scores and then dividing by the number of cases. Why was this a mistake?

The distribution of student test scores is severely left skewed. What would this mean?

An army recruit scored in the 80th percentile of incoming soldiers for a fitness test. What can we conclude about that soldier?

Researchers wish to compare the dispersion of student grades across eight universities of varying sizes. What strategy would allow them to properly compare grade dispersion across the eight distributions?

Which set of scores shows the greatest level of dispersion?

Suppose a distribution has an outlying value far smaller than the other values in the distribution. What will happen to the standard deviation if the outlier is removed?

Which of these statements describes the "least squares" principle?

What value is equal to the median?

What is the difference between central tendency and dispersion in a distribution of data?

What is the purpose of the expression ?(X_i) ?