Question 1

Restricting the range of a variable ___________ the effect on the correlation coefficient.

Accepted Answer

Restricting the range of a variable decreases the effect on the correlation coefficient. This is because limiting the range reduces the variability in the data, which in turn reduces the strength of the linear relationship between the variables.

Question 2

Brewster measures the height and age of four and five year-olds.To his surprise,he finds no correlation between height and age.What is most likely responsible for his results?

Accepted Answer

C) Restricting the range of the variables, in this case, age, limits the variability that can be observed. Normally, age and height are correlated in a broader age range, but by only looking at four and five-year-olds, the natural variation in growth rates among children of these close ages might not be enough to show a clear linear relationship.

Question 3

In a _____,a separate and distinct _____ is drawn to represent the number of people who received each possible score.

Accepted Answer

A bar graph is used to represent the number of people who received each possible score, and it usually consists of separate and distinct bars for each score. A polygon is a type of graph that is typically used to show the trend or pattern of data, and a pie chart is used to represent proportions or percentages of a whole. A line graph is also used to show trends over time, but it is not the most appropriate choice for a discrete set of scores. Therefore, the best choice is a bar graph, and option C is the only one that includes a bar graph as one of the answer choices.

Question 4

Ratio scales

Accepted Answer

Ratio scales have an absolute zero point, meaning that zero on the scale represents the complete absence of the characteristic being measured. This allows for meaningful comparisons and ratios between values.

Question 5

Structural equation models

Accepted Answer

Structural equation models are expected patterns of relationships among a set of variables. They are developed prior to analyzing and interpreting the data and can be used in both laboratory and field experiments.

Question 6

A teacher writes the results of a test on the board: 7 students received As,10 students received Bs,18 students received Cs,4 students received Ds,and 1 student received an F.In statistical terms,this is a

Accepted Answer

The results given by the teacher represent the frequency distribution of the test scores among the students. Therefore, the correct option is C, frequency distribution. Measures of central tendency (such as mean, median, and mode) and variability (such as range, variance, and standard deviation) require additional numerical data beyond the given frequencies. A correlation table requires pairs of numerical data for each student, which are not provided in the given information.

Question 7

Henry finds that for automobile owners,as the price of gasoline increases,the amount of miles they drive in a week decreases.This finding would suggest _____ relationship.

Accepted Answer

This finding suggests a negative relationship between the price of gasoline and the amount of miles driven in a week. As the price of gasoline increases, the amount of miles driven decreases. This is an inverse relationship, which is known as negative correlation.

Question 8

John finds the Pearson r correlation coefficient between variable A and variable B to be 0.00.Before concluding there is no relationship between the variables,John should

Accepted Answer

Constructing a scatterplot of the data is necessary to visually inspect the relationship between the variables. A Pearson correlation coefficient of 0.00 indicates no linear relationship between the variables, but there could still be a non-linear relationship or a relationship that is masked by outliers or non-normality. Therefore, it is essential to visualize the data using a scatterplot to make sure there is no relationship. A and B are not appropriate choices since changing the sample does not necessarily change the relationship, and restricting the range could eliminate potential relationships. D is not necessary since the coefficient already indicates no relationship.

Question 9

In a survey examining the number of 3^rd versus 6^th grade students who buy their lunch at school,the most appropriate description of the results would be to

Accepted Answer

The survey is examining the number of students who buy their lunch at school, so comparing the percentages of students in each group (3^rd and 6^th) who buy their lunch is the most appropriate way to describe the results. Comparing group means or correlating scores is not relevant since the survey is not measuring any particular variable or outcome that can be quantified. Comparing lunches is also not relevant as the survey is only asking about lunch-buying behavior.

Question 10

Which of the following is least correct regarding the effect size? The effect size

Accepted Answer

The effect size can range from negative infinity to positive infinity, not just from -1.0 to +1.0.

Question 11

Which one of the following would be an appropriate measure of central tendency to summarize ordinal data?

Accepted Answer

Ordinal data can be ordered or ranked, but the intervals between values cannot be determined. In this case, the median, which is the value that lies at the midpoint of the ranked data, would be the appropriate measure of central tendency. The mean should not be used because it assumes equal intervals between values, which is not the case for ordinal data. The correlation measures the strength and direction of the relationship between two variables, and the mode is the value that occurs most frequently, but neither of these measures is appropriate for summarizing ordinal data.

Question 12

When a line graph is employed to represent the number of subjects who received each possible score on a variable,this graph is called a frequency _____.

Accepted Answer

A frequency polygon is a line graph that shows the number of subjects who received each possible score on a variable, connecting the midpoints of each interval.

Question 13

In graphically depicting frequency distributions,_____ are used to display categorical variables while _____ are used to display quantitative variables.

Accepted Answer

Bar graphs are typically used to display categorical variables and histograms are typically used to display quantitative variables. Polygons can also be used to display quantitative variables, but they are less commonly used than histograms. Pie charts are used to display parts of a whole or proportions, and are not commonly used to display frequency distributions.

Question 14

In studying the effect of temperature on ice cream cone sales,a researcher could record the number of ice cream cones sold on cold versus hot days.The researcher would be most interested in

Accepted Answer

The researcher is interested in studying the effect of temperature on ice cream cone sales. The number of ice cream cones sold on cold versus hot days will give the researcher an idea of whether there is a difference in sales based on temperature. The researcher is comparing group means to determine the effect of temperature on ice cream cone sales.

Question 15

In a perfect positive relationship between two variables

Accepted Answer

In a perfect positive relationship, knowing one variable allows for exact prediction of the other, as they increase together perfectly.

Question 16

An ordinal scale of measurement lacks which one of the following properties of a scale?

Accepted Answer

An ordinal scale has equal orders, meaning that the items or categories being measured can be ranked in a meaningful way. However, it does not have equal intervals, meaning that the difference between one ranking and another cannot be assumed to be the same as the difference between other rankings on the scale.

Question 17

The finding that "the more classes a person takes,the more money they spend on textbooks" illustrates _____ relationship.

Accepted Answer

A positive relationship means that as one variable increases, so does the other variable. In this case, as the number of classes increases, the amount of money spent on textbooks also increases, indicating a positive relationship between the two variables.

Question 18

Dr.Greentree finds the r² value between days of sunlight (X)and plant growth (Y)to be +.48.Dr.Greentree can conclude

Accepted Answer

The +0.48 correlation coefficient (r) indicates a positive linear relationship between days of sunlight and plant growth. Since r² represents the proportion of variability explained by the correlation, we can conclude that 48% of the variability in plant growth can be accounted for by the number of days of sunlight. This means that other factors, such as soil quality or temperature, also affect plant growth. Option A is incorrect because the correlation coefficient does not represent a percentage of plants that will grow. Option B is incorrect because the correlation coefficient does not indicate a percentage increase in plant height. Option D is incorrect because the correlation coefficient does not suggest a decrease in plant growth on cloudy days.

Question 19

Which of the following is NOT true of the standard deviation? It

Accepted Answer

The standard deviation is the square root of the variance, not the square of the variance.

Question 20

Which one of the following is NOT one of the three basic ways of describing results discussed in your text?

Accepted Answer

The three basic ways of describing results discussed in the text are comparing group percentages, comparing group means, and correlating scores of individuals on two variables. Comparing group assignments is not a way of describing results, but rather a way of assigning participants to different groups in a study.

Quiz 12: Understanding Research Results: Describ-Ingvariables and Relationships Among Them

Restricting the range of a variable ___________ the effect on the correlation coefficient.

Brewster measures the height and age of four and five year-olds.To his surprise,he finds no correlation between height and age.What is most likely responsible for his results?

In a _,a separate and distinct _ is drawn to represent the number of people who received each possible score.

Ratio scales

Structural equation models

A teacher writes the results of a test on the board: 7 students received As,10 students received Bs,18 students received Cs,4 students received Ds,and 1 student received an F.In statistical terms,this is a

Henry finds that for automobile owners,as the price of gasoline increases,the amount of miles they drive in a week decreases.This finding would suggest _____ relationship.

John finds the Pearson r correlation coefficient between variable A and variable B to be 0.00.Before concluding there is no relationship between the variables,John should

In a survey examining the number of 3^rd versus 6^th grade students who buy their lunch at school,the most appropriate description of the results would be to

Which of the following is least correct regarding the effect size? The effect size

Which one of the following would be an appropriate measure of central tendency to summarize ordinal data?

When a line graph is employed to represent the number of subjects who received each possible score on a variable,this graph is called a frequency _____.

In graphically depicting frequency distributions,_ are used to display categorical variables while _ are used to display quantitative variables.

In studying the effect of temperature on ice cream cone sales,a researcher could record the number of ice cream cones sold on cold versus hot days.The researcher would be most interested in

In a perfect positive relationship between two variables

An ordinal scale of measurement lacks which one of the following properties of a scale?

The finding that "the more classes a person takes,the more money they spend on textbooks" illustrates _____ relationship.

Dr.Greentree finds the r² value between days of sunlight (X) and plant growth (Y) to be +.48.Dr.Greentree can conclude

Which of the following is NOT true of the standard deviation? It

Which one of the following is NOT one of the three basic ways of describing results discussed in your text?

Quiz 12: Understanding Research Results: Describ-Ingvariables and Relationships Among Them

Restricting the range of a variable ___________ the effect on the correlation coefficient.

Brewster measures the height and age of four and five year-olds.To his surprise,he finds no correlation between height and age.What is most likely responsible for his results?

In a _____,a separate and distinct _____ is drawn to represent the number of people who received each possible score.

Ratio scales

Structural equation models

A teacher writes the results of a test on the board: 7 students received As,10 students received Bs,18 students received Cs,4 students received Ds,and 1 student received an F.In statistical terms,this is a

Henry finds that for automobile owners,as the price of gasoline increases,the amount of miles they drive in a week decreases.This finding would suggest _____ relationship.

John finds the Pearson r correlation coefficient between variable A and variable B to be 0.00.Before concluding there is no relationship between the variables,John should

In a survey examining the number of 3rd versus 6th grade students who buy their lunch at school,the most appropriate description of the results would be to

Which of the following is least correct regarding the effect size? The effect size

Which one of the following would be an appropriate measure of central tendency to summarize ordinal data?

When a line graph is employed to represent the number of subjects who received each possible score on a variable,this graph is called a frequency _____.

In graphically depicting frequency distributions,_____ are used to display categorical variables while _____ are used to display quantitative variables.

In studying the effect of temperature on ice cream cone sales,a researcher could record the number of ice cream cones sold on cold versus hot days.The researcher would be most interested in

In a perfect positive relationship between two variables

An ordinal scale of measurement lacks which one of the following properties of a scale?

The finding that "the more classes a person takes,the more money they spend on textbooks" illustrates _____ relationship.

Dr.Greentree finds the r2 value between days of sunlight (X) and plant growth (Y) to be +.48.Dr.Greentree can conclude

Which of the following is NOT true of the standard deviation? It

Which one of the following is NOT one of the three basic ways of describing results discussed in your text?

In a _,a separate and distinct _ is drawn to represent the number of people who received each possible score.

In a survey examining the number of 3^rd versus 6^th grade students who buy their lunch at school,the most appropriate description of the results would be to

In graphically depicting frequency distributions,_ are used to display categorical variables while _ are used to display quantitative variables.

Dr.Greentree finds the r² value between days of sunlight (X) and plant growth (Y) to be +.48.Dr.Greentree can conclude