Question 1

If IQ scores are normally distributed,having a mean of 100 and a standard deviation of 15,approximately what percentage of people have IQ scores somewhere between 70 and 130?

Accepted Answer

The answer of If IQ scores are normally distributed,having a...

Question 2

Displaying data in a scatterplot can help us see the extent to which two variables are

Accepted Answer

A scatterplot is a visual representation of the relationship between two variables. Correlation refers to the extent to which two variables are related, so displaying data in a scatterplot can help us see the correlation between the variables. Random samples, normally distributed data, and standard deviations are not directly related to the use of a scatterplot.

Question 3

Which of the following statistical measures is most helpful for indicating the extent to which intelligence test scores can be used to predict grades in school?

Accepted Answer

The correlation coefficient measures the strength and direction of the relationship between two variables. In this case, it would measure the relationship between intelligence test scores and grades in school, indicating the extent to which one can predict the other. The mean, standard deviation, and range do not provide information about the relationship between two variables.

Question 4

A normal curve would approximate the distribution of

Accepted Answer

A normal curve would be a good approximation for the distribution of physical heights among American women because it is a continuous variable that is normally distributed. The distributions of males and females in the total American population, as well as the distribution of American children enrolled in each of the first through sixth grades, would be more likely to follow skewed or categorical distributions that would not be well approximated by a normal curve.

Question 5

If a set of standardized test scores is normally distributed,having a mean of 50 and a standard deviation of 10,approximately 68 percent of the group members receive scores somewhere between

Accepted Answer

The answer of If a set of standardized test scores...

Question 6

Approximately what percentage of the cases represented by the normal curve fall between -1 and +1 standard deviations from the mean?

Accepted Answer

The empirical rule states that approximately 68% of the cases represented by the normal curve fall within one standard deviation of the mean. Therefore, choice C is the correct answer.

Question 7

If a positive correlation between two sets of scores is displayed in a scatterplot,the points are clustered in a pattern that

Accepted Answer

A positive correlation means that as one variable increases, the other variable also increases. In a scatterplot, this is represented by a cluster of points that extends from the lower left to the upper right of the graph, as both variables are increasing. This is known as a positive linear relationship.

Question 8

Central tendency is to variation as ________ is to ________.

Accepted Answer

Central tendency measures (such as mean and median) provide information about the typical or central score in a distribution, while measures of variation (such as standard deviation) provide information about how spread out or dispersed the scores are around the central tendency. Therefore, central tendency is to variation as mean is to standard deviation.

Question 9

Although Dominick's psychology class is sometimes longer or shorter than usual,on average each class is 50 minutes.If the lengths of these classes form a normal curve,which statistic would enable Dominick to estimate the probability that any single class will last somewhere between 47 and 53 minutes?

Accepted Answer

The standard deviation is a measure of the spread or variability of the data in a normal distribution. By calculating the standard deviation of the class lengths, Dominick would be able to estimate the likelihood of any given class lasting between 47 and 53 minutes, which represents a range of +/- 1 standard deviation from the mean (50 minutes).

Question 10

If the points on a scatterplot are clustered in a pattern that extends from the upper left to the lower right,this would suggest that the two variables depicted are

Accepted Answer

A pattern extending from the upper left to the lower right indicates a negative correlation, meaning as one variable increases, the other decreases.

Question 11

Evelyn wants to know how consistent her bowling scores have been during the past season.Which of the following measures would tell her what she wants to know?

Accepted Answer

The standard deviation measures the variability or dispersion of a set of data. In this case, it would tell Evelyn how consistent or inconsistent her bowling scores have been throughout the season.

Question 12

Approximately 95 percent of the cases represented by the normal curve fall within ________ standard deviation(s)from the mean.

Accepted Answer

According to the empirical rule, approximately 68 percent of the cases fall within 1 standard deviation from the mean, approximately 95 percent of the cases fall within 2 standard deviations from the mean, and approximately 99.7 percent of the cases fall within 3 standard deviations from the mean. Therefore, approximately 95 percent of the cases fall within 2 standard deviations from the mean.

Question 13

Professor Connally uses a scatterplot to display the relationship between students' intelligence test scores and the number of failing grades they have received.The points on the scatterplot are most likely clustered in a pattern that

Accepted Answer

A negative correlation is expected, where higher intelligence test scores are associated with fewer failing grades, resulting in a pattern extending from the upper left to the lower right.

Question 14

Which of the following is a measure of the degree of variation among a set of scores?

Accepted Answer

Standard deviation is a measure of the degree of variation among a set of scores. The mean only measures central tendency, scatterplot is a visual representation of data points, and the correlation coefficient measures the strength and direction of the relationship between two variables.

Question 15

A graphed cluster of dots,each of which represents the values of two factors,is called a

Accepted Answer

A scatterplot is a graphed cluster of dots in which each dot represents the values of two factors. It is used to show the relationship between two variables. A bar graph is used to show a comparison between different groups or categories. A normal curve is a bell-shaped curve used to describe the distribution of data. A correlation coefficient is a numerical value that measures the strength and direction of the relationship between two variables.

Question 16

The symmetrical bell-shaped figure used to represent the distribution of many physical and psychological characteristics is called a

Accepted Answer

The symmetrical bell-shaped figure used to represent the distribution of many physical and psychological characteristics is called a normal curve. The normal curve is a mathematical concept that is widely used in statistics and probability theory to describe distributions of data. It is characterized by its shape, which is symmetrical and bell-shaped, with the majority of the data clustered around the mean and decreasing in frequency as you move away from the mean in either direction. A normal curve is also known as a Gaussian distribution, after the mathematician Carl Friedrich Gauss who first described it.

Question 17

Approximately what percentage of the cases represented by the normal curve fall between ‒3 and +3 standard deviations from the mean?

Accepted Answer

The answer of Approximately what percentage of the cases represented...

Question 18

To represent the correlation between two variables graphically,researchers often construct a

Accepted Answer

A scatterplot is the best choice for representing the correlation between two variables graphically. It displays the relationship between two continuous variables, with each variable plotted along one of the axes, and the plotted points representing the intersection of those values. The pattern of those plotted points can then reveal the nature of the correlation between the two variables.

Question 19

The difference between the highest and lowest scores in a distribution is the

Accepted Answer

The range is the difference between the highest and lowest scores in a distribution.

Question 20

Which of the following is a statistical measure of the relationship between two variables?

Accepted Answer

Correlation coefficient is a statistical measure that shows the degree to which two variables are related. It ranges between -1 and +1, where a negative value represents a negative correlation, positive value represents a positive correlation, and zero represents no correlation. Standard deviation, range, and mean are measures of central tendency and variability, but not specifically related to the relationship between two variables.

Quiz 16: Exploring the Role of Industrial-Organizational Psychology