Psych Stats: Exam 1

Which z-score corresponds to a score that is above the mean by 2 standard deviations? a. +2 b. +10 c. -2 d. This is impossible to determine without knowing the value of the standard deviation.

a. +2

A sample consists of n = 16 scores. How many of the scores are used to calculate the range? a. 2 scores b. 4 scores c. 8 scores d. 16 scores

a. 2 scores

For a sample with s = 9, a score of X = 67 corresponds to z = +1.00. What is the sample mean? a. M = 58 b. M = 76 c. M = 56 d. M = 78

a. M = 58

A person's phone bills for the last three months were $20, $75, and $55, respectively. What was the mean average amount for the three phone bills? a. $60 b. $50 c. $55 d. $65

b. $50

Which statement below is always false regarding a distribution of scores? a. 75% of the scores are above the mean b. 75% of the scores are above the median c. 75% of the scores are above the mode d. 75% of the scores are the same value as the mode

b. 75% of the scores are above the median

For an experiment comparing the effectiveness of two different teaching methods for improving the social skills of autistic children, the dependent variable would be the _____. a. experimental methodology b. autistic children c. teaching methods used to teach social skills d. levels of improvement in social skills among autistic children

d. levels of improvement in social skills among autistic children

For a sample, a score that is 12 points above the mean has a z-score of z = 1.20. What is the sample standard deviation? a. s = 4 b. s = 6 c. s = 8 d. s = 10

d. s = 10

A researcher uses an anonymous survey to investigate the social media habits of American college students. Based on the set of 300 surveys that were completed and returned, the researcher finds that students spend an average of 2 hours each day using social media. The group of 300 students who returned surveys is an example of a _____. a. parameter b. statistic c. population d. Sample

d. sample

Under which circumstance is a score that is 15 points above the mean an extreme score relatively far from the mean? a. when the population mean is much larger than 15 b. when the population standard deviation is much larger than 15 c. when the population mean is much smaller than 15 d. when the population standard deviation is much smaller than 15

d. when the population standard deviation is much smaller than 15

Which z-score value represents the location farthest from the mean? a. z = +0.50 b. z = -0.50 c. z = -1.00 d. z = -2.00

d. z = -2.00

A person scores X = 65 on an exam. Which set of parameters would give this person the worst grade on the exam relative to others? a. μ = 60 and σ = 10 b. μ = 60 and σ = 5 c. μ = 70 and σ = 10 d. μ = 70 and σ = 5

d. μ = 70 and σ = 5

If a set of exam scores forms a negatively skewed distribution, what can you likely conclude about the students' scores? a. Most of the students had relatively high scores. b. Most of the students had relatively low scores. c. About an equal number of students had relatively high and relatively low scores. d. It is not possible to draw any conclusions about students' scores with this information.

a. Most of the students had relatively high scores.

A population is the set of all individuals of interest in a particular study. a. True b. False

a. True

A research study uncovers that college graduates have higher lifetime work earnings than individuals who do not receive college degrees. This is an example of a correlational study. a. true b. false

a. True

A sample with a variance of s2 = 36 has a standard deviation equal to s = 6. a. True b. False

a. True

For a distribution of scores, the location identified by z = +1.00 and the location identified by z = -1.00 are the same distance from the mean. a. True b. False

a. True

For a population with μ = 75 and σ = 15, about 95% of the individuals will have scores between X = 45 and X = 105. a. True b. False

a. True

In August in Florida, the daily high temperatures are typically high with only a few relatively cool days. A frequency distribution graph showing daily average temperatures in Florida for August would probably form a negatively skewed distribution. a. True b. False

a. True

In a population with a mean of μ = 30 and a standard deviation of σ = 5, a score of X = 18 would be an extreme value, far out in the tail of the distribution. a. True b. False

a. True

It is possible for the value of the median to be greater than the value of the mode. a. True b. False

a. True

The classrooms in a Psychology department are numbered from 200 to 210. The department chair records the number of classes held in each room during the spring semester. If the results needed to be presented in a frequency distribution graph, the professor should use a bar graph. a. True b. False

a. True

The range and the variance are both measures of distance from the mean. a. True b. False

a. True

To determine the size of a difference between two individuals on a measured variable, a researcher must use either an interval or a ratio scale of measurement. a. True b. False

a. True

Using polling results from a sample of 100 registered voters in Iowa to predict the outcome of a statewide election set to take place one week later is an example of using inferential statistics. a. True b. False

a. True

Barbara scores X = 120 on a social work licensure exam for the state of Minnesota that has a mean of μ = 113 and a standard deviation of σ = 4. She moves to Wisconsin, and the state of Wisconsin is trying to determine which score she should receive on their licensure exam that has a mean of μ = 100 and standard deviation of σ = 8. Which score should Barbara receive on the Wisconsin licensure exam? (Hint: Transform the raw score to a z-score first!) a. X = 114 b. X = 112 c. X = 86 d. X = 106

a. X = 114

Which of the following is a critical aspect of the experimental method when examining the relationship between two variables? Select as many as necessary. a. manipulation of one variable b. observational study design c. random assignment of participants d. having a control group e. having one or more quasi-independent variables

a. manipulation of one variable c. random assignment of participants d. having a control group

Last week, Sarah had exams in her math and Spanish classes. On the math exam, the mean was μ = 30 with σ = 5, and Sarah had a score of X = 45. On the Spanish exam, the mean was μ = 60 with σ = 8, and Sarah had a score of X = 68. For which class should Sarah expect the better grade relative to her peers in each class? a. math b. Spanish c. The grades should be the same. d. There is not enough information provided to determine which is the better grade.

a. math

Students in an introductory art class are classified as art majors and non-art majors. Which scale of measurement is being used to classify the students? a. nominal b. ordinal c. interval d. Ratio

a. nominal

If a scores are shown in a bar graph, the scores were measured using a(n) _____ scale of measurement. a. nominal or ordinal b. ordinal or interval c. interval or ratio d. nominal or interval

a. nominal or ordinal

In a frequency distribution graph with negative skew, scores with the highest frequencies (think of the mode) are _____ of the distribution. a. on the right side b. on the left side c. in the middle d. represented at two distinct peaks

a. on the right side

For a research study examining how participant gender influences support for equality in society, participant gender is an example of which kind of variable? a. quasi-independent variable b. independent variable c. quasi-dependent variable d. dependent variable

a. quasi-independent variable

A positive z-score always corresponds to a score that is greater than the mean in a distribution. a. True b. False

a. true

Keith conducts a research study to examine how mental fatigue influences frustration levels. He has one group of participants complete a mentally exhausting problem-solving task for ten minutes, and a second group of participants complete an easy crossword puzzle for ten minutes. Then, he observes participant reactions to being prevented from achieving a desired goal on a second unrelated task as a measure of frustration levels. In this research study, the experimental condition is _____. a. whether or not they were mentally exhausted b. frustration levels c. easy versus hard crossword puzzle

a. whether or not they were mentally exhausted

If an entire population with μ = 60 and σ = 8 is transformed into z-scores, then the distribution of z-scores will have a mean of _____ and a standard deviation of _____. a. μ = 0; σ = 1 b. μ = 60; σ = 1 c. μ = 0; σ = 8 d. μ = 60; σ = 8

a. μ = 0; σ = 1

A population has μ = 50. Which value of σ would make X = 55 an extreme value out in the tail of the population distribution? a. σ = 1 b. σ = 6 c. σ = 10

a. σ = 1

On an exam with a mean of μ = 80, a person scores X = 90. Which of the following values for the standard deviation would position this person highest within the class? a. σ = 2 b. σ = 5 c. σ = 10 d. σ = 15

a. σ = 2

On an exam with μ = 52, a person scores X = 56. Which value for the standard deviation would give this person the highest position in the class distribution? a. σ = 2 b. σ = 4 c. σ = 8 d. This is impossible to determine based on the information provided.

a. σ = 2

A distribution of scores has a mean of 52, a median of 54, and a mode of 56. Based on this information, it appears that the distribution is symmetrical. a. True b. False

b. False

A high school gym teacher records the weights of students prior to beginning a fitness regimen. This is an example of measuring an ordinal variable. a. True b. False

b. False

A professor records the number of students who are absent each day for the semester. Given the scale of measurement used when measuring this variable, a bar graph should be used to show the frequency distribution. a. True b. False

b. False

A recent newspaper report describes that having more siblings causes increases in social skills. This is a valid statement to make given the correlational design of this research. a. True b. False

b. False

A recent study uncovered a correlation between gum disease and heart disease. This result indicates that gum disease causes individuals to develop heart disease. a. True b. False

b. False

A researcher records the list of finishes (e.g., 1st, 2nd, 3rd, 4th) for a track team throughout their season. The mean is the best measure of central tendency to report in this circumstance to describe the most typical finish for this track team. a. True b. False

b. False

A sample with a mean of M = 20 has ΣX = 120. There are n = 5 scores in this sample. a. True b. False

b. False

A sports historian records the number of times that the Minnesota Twins finished 1st, 2nd, 3rd, 4th, or 5th in their division for each of the last 20 years. If the results are presented in a frequency distribution graph, then a histogram should be used. a. True b. False

b. False

Approximately 80% of all scores in a distribution fall between 1 standard deviation of the mean. a. True b. False

b. False

Classifying people into groups based on college major is an example of measurement using an ordinal scale. a. True b. False

b. False

For a severely skewed distribution, the mean often provides a better measure of central tendency than the median or the mode. a. True b. False

b. False

For statistical purposes, there usually is not much reason to differentiate between interval and ordinal scales of measurement. a. True b. False

b. False

If a person scores X = 66 on an exam with μ = 70, they scored worse relative to others in the class if σ = 10 than if σ = 5. a. True b. False

b. False

In an introductory theater class, the professor records each student's favorite movie at the beginning of the semester. The teacher is measuring a continuous variable. a. True b. False

b. False

Individuals that score typically to others in a population following a treatment will tend to have extreme z-scores. a. True b. False

b. False

It is possible for a distribution to have more than one median. a. True b. False

b. False

Using the average score to describe a sample is an example of an inferential statistic. a. True b. False

b. False

A distribution of scores is positively skewed. Which is the most probable order, from smallest to largest, for the three measures of central tendency? a. Mean, median, mode b. Mode, median, mean c. Mean, mode, median d. Median, mean, mode

b. Mode, median, mean

The mode is the only measure of central tendency that is appropriate to utilize for a variable measured with which scale of measurement? a. ordinal b. Nominal c. interval d. Ratio

b. Nominal

For a population with μ = 100 and σ = 20, what is the X value corresponding to z = -0.25? a. X = 85 b. X = 95 c. X = 105 d. X = 115

b. X = 95

Which type(s) of graph(s) should be used for data that come from a nominal scale of measurement? a. histograms b. bar graphs c. histograms or bar graphs d. bar graphs or line/polygons

b. bar graphs

Which position in a distribution corresponds to a z-score of z = -1.00? a. below the mean by 1 point b. below the mean by 1 standard deviation c. above the mean by 1 point d. above the mean by 1 standard deviation

b. below the mean by 1 standard deviation

Inferential statistics allow researchers to _____. a. describe data sets b. make predictions and generalizations about populations c. operationally define a construct d. verify the validity of a research study

b. make predictions and generalizations about populations

A graph represents frequencies associated with scores for a variable with vertical bars that have space between them. Which scale of measurement was used to measure this variable? a. nominal b. nominal or ordinal c. interval or ratio d. Interval or ordinal

b. nominal or ordinal

The participants in a research study self-report their sleep quality levels by choosing the response option that best characterizes their average sleep quality per night from the following response options: 1 = extremely low sleep quality, 2 = very low sleep quality, 3 = low sleep quality, 4 = extremely high sleep quality. Which measurement scale is being used to classify sleep quality? a. nominal b. ordinal c. interval d. Ratio

b. ordinal

The students in a psychology class seem to think that the midterm exam was very difficult. If they are correct, what is the most likely shape for the distribution of exam scores? a. symmetrical b. positively skewed c. negatively skewed d. normal

b. positively skewed

A researcher is measuring the amount of time needed to solve a set of anagrams for a sample of n = 15 students. However, one of the participants fails to solve the problems so the researcher has an undetermined score. What is the best measure of central tendency for these data? a. the mean b. the median c. either the mean or mode d. either the mean or median

b. the median

Under which circumstance below is the median likely to be a better measure of central tendency than the mean? a. with a symmetrical distribution b. with an extremely skewed distribution c. when the data consist of nominal measurements d. when the data come from a continuous variable.

b. with an extremely skewed distribution

What is the median for the following set of scores? Scores: 1, 5, 11, 12, 20 a. 5 b. 11.5 c. 11 d. 8

c. 11

What is the value of the median for the following set of scores? Scores: 1, 4, 6, 7, 9, 15, 15, 16, 25, 30 a. 11 b. 8 c. 12 d. 15

c. 12

Which set of scores below has the smallest standard deviation? (Hint: no need to calculate - look at the range of the data) 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 sample of n = 11 scores? Scores: 1, 2, 2, 2, 3, 3, 4, 5, 6, 6, 7 a. 6 b. 3 c. 2 d. 2.5

c. 2

Consider a population that has a score of X = 15 associated with a z-score of +1.50. What does this z-score indicate about the location of X = 15? a. A score of X = 15 is 1.5 mean units below the standard deviation. b. A score of X = 15 is 1.5 mean units above the standard deviation. c. A score of X = 15 is 1.5 standard deviations above the mean. d. A score of X = 15 is 1.5 standard deviations below the mean.

c. A score of X = 15 is 1.5 standard deviations above the mean.

Consider the distribution of exam scores for the first exam within a college course. If the set of exam scores forms a symmetrical distribution, what can be concluded about the students' scores? a. Most of the students had relatively high scores. b. Most of the students had relatively low scores. c. About an equal number of students had relatively high and relatively low scores. d. A substantial number of students had very high scores and a substantial number of students had very low scores.

c. About an equal number of students had relatively high and relatively low scores.

To display the distribution of grades (A, B, C, D, F) for all students in the course, it would be appropriate to use: a. A pie chart but not a bar graph b. A bar graph but not a pie chart c. Either a pie chart or a bar graph

c. Either a pie chart or a bar graph

What is an advantage of measuring variables on an interval scale compared to an ordinal scale? a. Interval scales, but not ordinal scales, tell whether the measurements are the same or different b. Interval scales, but not ordinal scales, tell the direction of the difference c. Interval scales, but not ordinal scales, tell the size of the difference d. Interval scales, but not ordinal scales, whether the measurements are reliable

c. Interval scales, but not ordinal scales, tell the size of the difference

Which statement below is true? a. It is possible for a distribution of scores to have two means. b. It is possible for a distribution of scores to have two means or two medians. c. It is possible for a distribution of scores to have two modes. d. It is possible for a distribution of scores to have two medians or two modes.

c. It is possible for a distribution of scores to have two modes.

A sample of n = 6 scores has a mean of M = 5. One person with a score of X = 19 is added to the distribution. What is the mean for the new set of scores? a. M = 5 b. M = 6 c. M = 7 d. M = 8

c. M = 7

A researcher assesses eye color for a sample of n = 50 people. Which measure of central tendency would be appropriate to summarize the measurements of eye color collected for this sample? a. Mean b. Median c. Mode d. Any of the three measures of central tendency could be used

c. Mode

A population with a mean of μ = 9 has ΣX = 54. How many scores are in the population? (Hint: think of the formula for calculating the mean) a. N = 9 b. N = 7 c. N = 6 d. N = 14

c. N = 6

A population of N = 5 scores has a mean of μ = 20 and a standard deviation of σ = 4. Which of the following is the correct interpretation of the standard deviation? a. The average distance of scores from the mean of μ = 20 is 5 points. b. The average distance of scores from the mean of μ = 20 is 1 point. c. The average distance of scores from the mean of μ = 20 is 4 points. d. The average squared distance of scores from the mean of μ = 20 is 4 points.

c. The average distance of scores from the mean of μ = 20 is 4 points.

In N = 25 games last season, the college basketball team averaged μ = 83 points with a standard deviation of σ = 8. In their final game of the season, the team scored 78 points. Based on this information, the number of points scored in the final game was _____. a. a little above average b. far below average c. a little below average d. There is not enough information provided to know

c. a little below average

The main distinction between an interval and ratio scale of measurement is that _____. a. a score of 0 on a ratio scale does not represent the complete absence of that variable b. a ratio scale does not allow for comparisons between two scores regarding whether one score is higher or lower than the other c. a score of 0 on a ratio scale represents the complete absence of that variable d. a ratio scale does not allow for comparisons between two scores regarding differences in size

c. a score of 0 on a ratio scale represents the complete absence of that variable

The amount of time (0-60 seconds) that it takes a person to solve a problem is an example of a(n) _____ variable. a. independent b. nominal c. continuous d. Discrete

c. continuous

Organizing a set of scores in a table or computing an average to summarize a data set is an example of using ______. a. parameters b. random sampling c. descriptive statistics d. inferential statistics

c. descriptive statistics

Which type(s) of graph(s) should be used for data that come from an interval scale of measurement? a. histograms or bar graphs b. bar graphs c. histograms or line/polygons d. histograms, bar graphs, or line/polygons

c. histograms or line/polygons

A recent study reported that students who just finished playing a prosocial video game were more likely to help others than students who had just finishing playing a neutral or antisocial game. For this study, the kind of game given to the students was the _____. a. control group b. quasi-independent variable c. independent variable d. dependent variable

c. independent variable

It is only appropriate and possible to calculate the variance and standard deviation as measures of variability for variables measured using a(n) _____ scale of measurement. a. ordinal b. ratio c. interval or ratio d. ordinal or nominal

c. interval or ratio

A sample of scores has a mean of M = 26, a median of 28, and a mode of 29. What is the most likely shape for the sample distribution? a. symmetrical b. positively skewed c. negatively skewed d. cannot be determined from the information given

c. negatively skewed

If the categories are independent from each other and unable to be ordered meaningfully, then it is an example of a(n) _____ variable. a. interval b. ordinal c. nominal d. Continuous

c. nominal

A researcher uses an anonymous survey to investigate the television-viewing habits of 100 American adolescents. The researcher plans to make an inference about the television-viewing habits of all American adolescents based on the results of the survey. The entire group of American adolescents is an example of a _____. a. sample b. statistic c. population d. Parameter

c. population

Which of the following phrases is not consistent with central tendency as a statistical measure? a. average score b. most typical score c. spread of scores d. middle score

c. spread of scores

An introductory to psychology professor has students report their major on the first day of classes. Then, the professor decides to determine the major that is most representative of the students in their class. Which measure of central tendency should they utilize? a. the mean b. the median c. the mode d. the weighted average

c. the mode

Which of the following symbols identifies the population standard deviation? a. s b. N c. σ d. σ2

c. σ

What is the mean for the following sample of scores? Scores: 2, 4, 5, 9 a. 20 b. 4.5 c. 4 d. 5

d. 5

A population of N = 10 scores has μ = 21 and σ = 3. What is the population variance? a. 7 b. 100 c. 2 d. 9

d. 9

Sarah is conducting a research study in which she randomly assigns one group of participants to consume one cup of coffee and then randomly assigns another group of participants consume only water. Then, she assesses attention levels of these participants following coffee consumption. This is an example of a(n) _____ research study. a. descriptive b. correlational c. quasi-experimental d. Experimental

d. Experimental

Which statement below regarding populations is true? a. Populations typically are small in size. b. Populations cannot consist of non-human animal research subjects. c. The experimental research method should be used to examine populations. d. It usually is challenging to obtain data from every person in a population.

d. It usually is challenging to obtain data from every person in a population.

What scale of measurement is being used when a researcher measures the amount of car accidents that participants have been involved in during their lifetime? a. nominal b. ordinal c. interval d. Ratio

d. Ratio

A researcher surveys a sample of n = 200 college students and asks each person to identify their favorite movie among 10 choices. Which kind of graph should be used to present these results? a. histogram b. polygon c. pie chart d. bar graph

d. bar graph