Psychological Statistics Unit 1

A recent study found a correlation between gum disease and heart disease. This result indicates that gum disease causes people to develop heart disease.​ True False

False

A researcher interested in vocabulary development obtains a sample of 3-year-old children to participate in a research study. The average score for the group of children is an example of a parameter.​ True False

False

Classifying people into two groups on the basis of gender is an example of measurement on an ordinal scale. True False

False

For the following scores, Σ X^2 = 49. Scores: 1, 4, 2, 0 ​ True False

False

The final step in computing Σ(X + 1)2 is to square the sum of the (X + 1) values.​ True False

False

The final step in computing Σ(X + 1)^2 is to square the sum of the (X + 1) values.​ True False

False

To compute Σ X 2 , you first add the scores, then square the total. True False

False

To compute Σ X^2 , you first add the scores, then square the total. True False

False

A correlational study is used to examine the relationship between two variables but cannot determine whether it is a cause-and-effect relationship.​ True False

True

A recent report concluded that college graduates have higher life-satisfaction scores than individuals who do not receive college degrees. For this study, graduating versus not graduating is an example of a quasi-independent variable.​ True False

True

A researcher is interested in the average income for registered voters in the United States. The entire group of registered voters is an example of a population.​ True False

True

If a researcher measures two individuals on a nominal scale, it is impossible to determine which individual has the larger score. True False

True

If a researcher measures two individuals on an ordinal scale, it is impossible to determine how much difference exists between the two people.​ True False

True

In an introductory theater class, the professor records each student's favorite movie from the previous year. The teacher is measuring a discrete variable.​ True False

True

Recording the number of text messages you receive each day would be an example of measuring a discrete variable.​ True False

True

The first step in computing Σ(X + 1) is to add 1 point to each score.​ True False

True

The goal for an experiment is to demonstrate that changes in one variable are responsible for causing changes in a second variable.​ True False

True

To determine how much difference there is between two individuals, you must use either an interval or a ratio scale of measurement.​ True False

True

What is the value of Σ(X + 1) for the scores 1, 0, 1, 4? a. 10 b. 4 c. 7 d. 6

a. 10

What is the value of Σ(X + 1) for the scores 2, 4, 7? a. 16 b. 11 c. 13 d. 10

a. 16

What is the value of ΣX2 for the scores 1, 0, 2, 4? a. 21 b. 28 c. 14 d. 49

a. 21

For a research study comparing attitude scores for males and females, participant gender is an example of what kind of variable? a. A quasi-dependent variable b. An independent variable c. A quasi-independent variable d. A dependent variable

a. A quasi-dependent variable

What is the first step to be performed when computing Σ(X + 2)^2 ? a. Add 2 points to each score b. Sum the squared values c. Sum the (X + 2) values d. Square each value

a. Add 2 points to each score

Suppose a class takes a quiz and the majority of scores are high with fewer low scores. Which is the most likely shape of the distribution? a. Negatively Skewed b. Positively skewed c. Normal d. Symmetrical

a. Negatively Skewed

The average verbal SAT score for the entire class of entering freshmen is 530. However, if you select a sample of 20 freshmen and compute their average verbal SAT score you probably will not get exactly 530. What statistical concept is used to explain the natural difference that exists between a sample mean and the corresponding population mean? a. Sampling error b. Statistical error c. Parametric error d. Inferential error

a. Sampling error

What is the first step to be performed in the following mathematical expression, ΣX^2 ? a. Square each score b. Add the squared scores c. Add the scores d. Square the sum of the scores

a. Square each score

What is the first step to be performed in the following mathematical expression, ΣX^2 ? a. Square each score b. Add the squared scores c. Square the sum of the scores d. Add the scores

a. Square each score

A histogram would be used instead of a bar graph if ________ a. The variable is continuous b. The variable is discrete c. The distribution is skewed d. The distribution is symmetrical

a. The variable is continuous

Which of the following is a continuous variable? a. Weight b. Placement in a race c. Number of traffic tickets received in a year d. College major

a. Weight

Under what circumstances is the median likely to produce a better measure of central tendency than the mean? a. With an extremely skewed distribution b. With a symmetrical distribution c. When the data consist of a variable measured on a nominal scale. d. When the data are numerical scores from an interval or a ratio scale

a. With an extremely skewed distribution

A professor wants to represent how many people are morning people versus evening people. Which type of graph would be best to use in this scenario? a. bar graph b. histogram c. frequency polygon (line graph) d. either a histogram or frequency polygon

a. bar graph

You decide to collect information from 500 participants on their level of education obtained (no high school diploma, high school diploma, Associate's Degree, Bachelor's, etc). Which type of graph would be best to use in this scenario? a. bar graph b. histogram c. frequency polygon (line graph) d. either a histogram or frequency polygon

a. bar graph

Cause/effect questions are the type of questions used by which method of research? a. experimental b. nonexperimental c. correlational d. quasi-experimental

a. experimental

After measuring two individuals, a researcher can say that Tom's score is 4 points higher than Bill's. The measurements must come from a(n) _______ scale. a. interval or ratio b. nominal c. ordinal d. interval

a. interval or ratio

A researcher uses an anonymous survey to investigate the television-viewing habits of American adolescents. The goal of the research is to determine the average number of hours each day that American adolescents spend watching television. The researcher is trying to determine a number that is an example of a _____. a. parameter b. statistic c. sample d. population

a. parameter

A researcher uses an anonymous survey to investigate the television-viewing habits of American adolescents. The entire group of American adolescents is an example of a _________. a. population b. statistic c. parameter d. sample

a. population

Although a research study is typically conducted with a relatively small group of participants known as a _________, most researchers hope to generalize their results to a much larger group known as a _________. a. sample; population b. population; sample c. statistic; sample d. parameter; population

a. sample; population

A characteristic, usually a numerical value, which describes a sample is called a _______. a. statistic b. parameter c. constant d. variable

a. statistic

A standard deviation is conceptually most similar to what? a. the average of all deviations b. the square of the variance c. the square root of the standard error d. the highest score minus the lowest score

a. the average of all deviations

If the variance of a dataset is 16, what is the standard deviation? a. 2 b. 4 c. 16 d. 256

b. 4

What is the value of Σ(X - 2) for the scores 2, 3, 5? a. 10 b. 4 c. 8 d. 6

b. 4

What is the value of (ΣX)^2 for the scores 1, 0, 2, 4? a. 14 b. 49 c. 21 d. 28

b. 49

What is a common way that researchers, organizations and news sources create a misleading graph? a. Change the range of scale units on the x-axis b. Change the range of scale units on the y-axis. c. Use a bar graph instead of a histogram. d. Use a histogram instead of a bar graph.

b. Change the range of scale units on the y-axis.

Which of the following is true about the difference between interval and ratio scales a. Interval variables can not have a score of zero, but ratio scales can b. Interval scales may have a score of 0, but (unlike with ratio scales), but it does not represent the true absence of what is measured. c. Ratio variables can not have a score of zero, but interval scales can d. Ratio scales may have a score of 0, but (unlike with interval scales) it does not represent the true absence of what is measured.

b. Interval scales may have a score of 0, but (unlike with ratio scales), but it does not represent the true absence of what is measured.

A population of scores has a mean = 26, median = 23, and mode = 22. What is the most likely shape for the population distribution?? a. Normal b. Positively skewed c. Negatively skewed d. Cannot be determined

b. Postively skewed

A recent study reports that students who just finished playing a prosocial video game were more likely to help others than students who had played a neutral or antisocial game. For this study, what is the independent variable? a. The students who were given the neutral or antisocial game b. The kind of game given to the students c. The students who were given the prosocial game d. The helping behavior of the students

b. The kind of game given to the students

The relationship between a statistic and a parameter is the same as the relationship between ______. a. a statistic and a parameter b. a sample and a population c. descriptive statistics and inferential statistics d. a parameter and a population

b. a sample and a population

In an experiment, the independent variable is _______ by the experimenter a. measured b. manipulated c. both measured and manipulated d. neither measured nor manipulated

b. manipulated

Which of the following is an example of a discrete variable? a. temperature of a room b. number of children in a family c. amount of weight loss d. time to run one mile

b. number of children in a family

Using letter grades (A, B, C, D, and F) to classify student performance on an exam is an example of measurement on a(n) _______ scale of measurement. a. interval b. ordinal c. ratio d. nominal

b. ordinal

A researcher uses an anonymous survey to investigate the television-viewing habits of American adolescents. Based on the set of 356 surveys that were completed and returned, the researcher finds that these students spend an average of 3.1 hours each day watching television. For this study, the set of 356 students who returned surveys is an example of a _______. a. population b. sample c. statistic d. parameter

b. sample

A problem with using the mode as a measure of central tendency is that a. it is the most difficult one to calculate b. the same set of data can produce more than one mode c. it tends to overestimate what is actually the central tendency d. it can only be applied to qualitative variables

b. the same set of data can produce more than one mode

You are instructed to subtract 4 points from each score and find the sum of the resulting values. How would this set of instructions be expressed in summation notation? a. Σ(4 - X) b. Σ (X - 4) c. 4 - ΣX d. ΣX - 4

b. Σ (X - 4)

You are instructed to subtract 4 points from each score, square the resulting value, and find the sum of the squared numbers. How would this set of instructions be expressed in summation notation? a. ΣX - 4^2 b. Σ(X - 4)^2 c. (ΣX - 4)^2 d. ΣX^2 - 4

b. Σ(X - 4)2

What is the value of Σ(X - 1)^2 for the scores 1, 2, 1, 4? a. 36 b. 49 c. 10 d. 16

c. 10

Which set of scores has the least amount of variability? a. 11, 17, 31, 53 b. 5, 11, 42, 22 c. 145, 143, 145, 147 d. 27, 105, 10, 80

c. 145, 143, 145, 147

What is the mode for the following set of score: 3, 3, 1, 5, 8, 7, 6, 9, 10 a. 5.78 b. 8 c. 3 d. 6

c. 3

What is the first step to be performed when computing Σ(X + 2)^2 ? a. Sum the (X + 2) values b. Square each value c. Add 2 points to each score d. Sum the squared values

c. Add 2 points to each score

What is the first step to be performed when computing Σ(X + 2)^2 ? a. Sum the (X + 2) values b. Sum the squared values c. Add 2 points to each score d. Square each value

c. Add 2 points to each score

Which of the following is done last in the order of operations? a. Multiplication b. Summation (Σ) c. Addition d. Squaring

c. Addition

A group of researchers thought that the amount of time alloted to take a quiz would cause changes in students' frustration levels. What was their dependent variable? a. Amount of time b. Quiz grades c. Frustration levels d. Speed of completing quiz

c. Frustration levels

Reaction time is a commonly used variable in psychological research. Reaction times are usually close to the minimum possible time but sometimes take considerably longer. Distributions of reaction times are most likely: a. Negatively Skewed b. Symmetrical c. Positively skewed d. Bimodal

c. Positively skewed

A researcher conducts an experiment to determine whether moderate doses of St. John's Wort have any effect on memory for college students. For this study, what is the independent variable? a. The memory score for each participant b. Cannot answer without more information c. The amount of St. John's Wort given to each participant d. The group of college students

c. The amount of St. John's Wort given to each participant

Which of the following is an example of a continuous variable? a. The number of children in a family b. The gender of each student in a psychology class c. The amount of time to solve a problem d. The number of males in each class offered by the college

c. The amount of time to solve a problem

A recent study reports that students who just finished playing a prosocial video game were more likely to help others than students who had played a neutral game. For this study, what is the independent variable? a. The students who were given the prosocial game b. The students who were given the neutral game c. The kind of game given to the students d. The helping behavior of the students

c. The kind of game given to the students

A recent study reports that students who just finished playing a prosocial video game were more likely to help others than students who had played a neutral game. For this study, what is the independent variable?? a. The students who were given the prosocial game b. The students who were given the neutral game c. The kind of game given to the students d. The helping behavior of the students

c. The kind of game given to the students

A recent study reports that students who just finished playing a prosocial video game were more likely to help others than students who had played a neutral or antisocial game. For this study, what is the independent variable? a. The helping behavior of the students b. The students who were given the neutral or antisocial game c. The kind of game given to the students d. The students who were given the prosocial game

c. The kind of game given to the students

The heigth of each bar on a frequency histogram represents a. The total number of scores in the sample b. The total number of participants in the sample c. The total number of participants who scored that particular score d. The total number of scores for that particular participant

c. The total number of participants who scored that particular score

The relationship between a statistic and a parameter is the same as the relationship between ______. a. a statistic and a parameter b. descriptive statistics and inferential statistics c. a sample and a population d. a parameter and a population

c. a sample and a population

An example of a variable measured on an ordinal scale is a. name of college attending b. number of college credits completed c. college classification (freshman, sophomore, etc.) d. room temperature (in degrees Fahrenheit)

c. college classification (freshman, sophomore, etc.)

If it is impossible to divide the existing categories of a variable, then it is an example of a(n) _____ variable. a. continuous b. independent c. discrete d. dependent

c. discrete

If it is impossible to divide the existing categories of a variable, then it is an example of a(n) _____ variable. a. independent b. dependent c. discrete d. continuous

c. discrete

The type of treatment used in a research study describes the a. continuous variable b. dependent variable c. independent variable d. outcome variable

c. independent variable

What scale of measurement is used for quantitative variables, but has an arbitrary zero point? a. nominal b. ordinal c. interval d. ratio

c. interval

After measuring two individuals, a researcher can say that Tom's score is 4 points higher than Bill's. The measurements must come from a(n) _______ scale. a. interval b. ordinal c. interval or ratio d. nominal

c. interval or ratio

Which of the following is an example of a discrete variable?? a. time to complete a test b. weight of fish caught at a lake c. number of stoplights in a city d. height of buildings in a town

c. number of stoplights in a city

A researcher is curious about the average monthly cell phone bill for high school students in the state of Florida. If this average could be obtained, it would be an example of a ______. a. statistic b. sample c. parameter d. population

c. parameter

For an experiment comparing two methods of teaching social skills training to autistic children, the independent variable is _______ and the dependent variable is _______. a. teaching methods; the autistic children b. the social skills that are learned; the autistic children c. teaching methods; the social skills that are learned d. the autistic children; the social skills that are learned

c. teaching methods; the social skills that are learned

What is the value of Σ(X - 1)^2 for the scores 1, 2, 1, 4? a. 36 b. 16 c. 49 d. 10

d. 10

What is the value of ΣX + 1 for the scores 1, 6, 3? a. 10 b. 13 c. 16 d. 11

d. 11

What is the median for these scores (4, 1, 8, 6)? a. 2.5 b. 4 c. 4.5 d. 5

d. 5

If a distribution has two scores that are tied for most common, which is the mode? a. The lower score. b. The higher score. c. The average of the two scores. d. Both scores are the mode.

d. Both scores are the mode.

Bar graphs are used to represent the frequency for which type of variables? a. Only nominal b. Interval and Ratio c. Only interval d. Nominal and Ordinal

d. Nominal and Ordinal

Which of the following is most likely a continuous variable? a. Number of children in a family b. Number of vacations taken per year c. Type of therapy used d. Temperature in Celsius

d. Temperature in Celsius

Which of the following is an example of a discrete variable? a. The amount of weight gained for each freshman at a local college b. The age of each student in a psychology class c. The amount of time to solve a problem d. The gender of each student in a psychology class

d. The gender of each student in a psychology classAnswers

A researcher is interested in the impact of natural surroundings on brainstorming. She randomly assigns some invidviduals to brainstorm as many uses A researcher is interested in the impact of natural surroundings on brainstorming. She randomly assigns some invidviduals to brainstorm as many uses of a brick in a garden and others to do the same brainstorming task in a cubicle. The independent variable in this scenario is... a. The garden group b. creativity c. The cubicle group d. The location of the brainstorming task

d. The location of the brainstorming task

If Group 1 in your study has a standard deviation of 10 and Group 2 in your study has a standard deviation of 5, then you know that a. Group 1 has more scores in it than Group 2 b. Group 1 has a greater range of scores than Group 2. c. The x scores in Group 1 are two times larger than the x scores in Group 2. d. The scores in Group 1 are more spread out than the scores in Group 2.

d. The scores in Group 1 are more spread out than the scores in Group 2.

What additional information is obtained by measuring two individuals on an interval scale compared to an ordinal scale? a. The direction of the difference b. None of the other options is correct c. Whether the measurements are the same or different d. The size of the difference

d. The size of the difference

Using letter grades (A, B, C, D, and F) to classify student performance on an exam is an example of measurement on a(n) _______ scale of measurement. a. nominal b. ratio c. interval d. ordinal

d. ordinal