Question 1

Two students in an art class are at least 20 years older than the others.Which measure of variation of class members' ages is most affected by the ages of these two students?

Accepted Answer

The range is the difference between the highest and lowest values in a data set, so it is directly affected by the presence of two students who are at least 20 years older than the others. The mode is the most frequently occurring value and is not influenced by outliers, so it is not the best choice. The median is the middle value in a data set and is also not influenced greatly by outliers. The standard deviation measures how spread out the data is from the mean and would be affected by outliers, but it is not the best choice as the question asks specifically about the two oldest students' effect on the variation.

Question 2

Standard deviation is to mean as ________ is to ________.

Accepted Answer

Standard deviation measures the variation or spread of a set of data around the mean, just as a measure of variation is related to a measure of central tendency (such as mean or median). Therefore, B is the best answer. The other choices are not related to the concept of standard deviation in the same way.

Question 3

Variation is to central tendency as range is to

Accepted Answer

Variation and range both measure the spread or dispersion of data, while central tendency and mode both relate to the most common or typical value in a dataset.

Question 4

The mode of a distribution of scores is the

Accepted Answer

The mode is the score that appears most frequently in a distribution of scores.

Question 5

The most familiar measure of central tendency is the

Accepted Answer

The mean is the most commonly used measure of central tendency and is defined as the average of a set of numbers. It is calculated by adding up all the numbers in the set and dividing by the total number of values.

Question 6

Professor Woo noticed that the distribution of her students' scores on the last biology test had an extremely small standard deviation.This indicates that the

Accepted Answer

A small standard deviation indicates that the scores are close together and not spread out, therefore the students' scores tended to be very similar to one another.

Question 7

The percentage of students whose average grades fall into various performance levels could be represented by a

Accepted Answer

A bar graph is a commonly used tool for visualizing the distribution of data across different categories, in this case, the performance levels of students based on their average grades. It provides a clear and easy-to-read picture of the proportion of students falling into each performance level, making it an ideal choice for representing this type of data. Standard deviation is a measure of the spread of data around the mean and is not suitable for representing the distribution of individual data points in different categories. Mode is a measure of central tendency and does not provide information on the range or distribution of data. Correlation is a statistical measure of the relationship between two variables and is not applicable in this case.

Question 8

To understand the British newspaper headline "Income for 62% Is Below Average," a reader needs to appreciate the distinction between the ________ and the mean.

Accepted Answer

The median represents the middle value in a set of data when arranged in order. Unlike the mean, it is not affected by extreme values (outliers). Therefore, if 62% of people have incomes below the median, it is possible for their incomes to be classified as "below average" even if the mean income is higher due to a small number of very high earners.

Question 9

Seven members of a girls' club reported the following individual earnings from their sale of raffle tickets: $5,$9,$4,$11,$6,$4,and $3.In this distribution of individual earnings,the

Accepted Answer

The answer of Seven members of a girls' club reported...

Question 10

Which of the following provides only a rough indication of the degree of variation among a set of scores?

Accepted Answer

Range provides only a rough indication of the degree of variation among a set of scores because it only measures the difference between the highest and lowest score and does not take into account the distribution of scores in between. Skewed refers to the shape of the distribution, standard deviation measures the spread of the scores around the mean, and median is a measure of central tendency.

Question 11

The mode,median,and mean are most likely to have different values when they

Accepted Answer

Skewed distributions have a longer tail on one side, which can pull the mean in that direction and away from the median and mode. This results in the mode, median, and mean having different values.

Question 12

The mode,median,and mean are measures of

Accepted Answer

The mode, median, and mean are all measures of central tendency, representing the typical or central value of a set of data.

Question 13

Measures of central tendency are most useful for

Accepted Answer

Measures of central tendency, such as the mean, median, and mode, are used to summarize data by finding a typical or representative value. They are not used to determine statistical significance, extrapolate from the sample to the population, or enable measurement of more variable groups.

Question 14

In a distribution of test scores,which measure of central tendency would likely be the most affected by a couple of extremely high scores?

Accepted Answer

The mean is the measure of central tendency that takes into account all scores in the distribution, whereas the median and mode are less affected by extreme scores. If there are a couple of extremely high scores in the distribution, they will greatly increase the sum of scores, leading to a higher mean.

Question 15

The arithmetic average of a distribution of scores is the

Accepted Answer

The arithmetic average is represented by the mean of a distribution of scores. The mode is the most frequently occurring score, the median is the value that separates the higher half from the lower half of scores, and the standard deviation is a measure of the amount of variation or dispersion in the data. Therefore, the best choice is D as it accurately represents the arithmetic average.

Question 16

Seven members of a debate club reported the following individual earnings from their sale of cakes: $7,$13,$3,$5,$2,$9,and $3.In this distribution of individual earnings,the

Accepted Answer

Mean = (7+13+3+5+2+9+3)/7 = 42/7 = 6
Median = middle value = 5
Mode = most frequently occurring value = 3
Therefore, the mean is greater than the mode and greater than the median.

Question 17

The standard deviation is a measure of

Accepted Answer

The standard deviation is a measure of variation, specifically how much the data points deviate from the mean. It is not a measure of central tendency (which would be represented by the mean or median), statistical significance, or skewness.

Question 18

The range is

Accepted Answer

The range is the difference between the highest and lowest scores in a distribution. It is a measure of variation that reflects the spread of scores in a distribution.

Question 19

For which of the following distributions of scores would the median most clearly be a more appropriate measure of central tendency than the mean?

Accepted Answer

The distribution in D has a significant outlier (18), which would skew the mean, making the median a more appropriate measure of central tendency to represent the central value of the dataset.

Question 20

Six different students spent $10,$13,$2,$12,$13,and $4,respectively,on entertainment.The mode of this group's entertainment expenditures is

Accepted Answer

The mode is the number that appears most frequently in the group. In this case, the number 13 appears twice, which is more than any other number, making it the mode.

Quiz 3: Research Strategies: How Psychologists Ask and Answer Questions