Ch 1-4 Chk & Review Psy Stat

What is the mode for the following sample of n = 8 scores? Scores: 0, 1, 1, 1, 2, 2, 3, 3​ Question 18 options:​ 1​ 1.5​ 13/8 = 1.625 ​3

1

For the following distribution, how many people had scores less than X = 20?​ X f 20-25 2 15-19 5 10-14 4 5-9 1 Question 8 options: ​5 ​10 ​11 ​12

10

What is the total number of scores for the distribution shown in the following table?​ X f 4 3 3 5 2 4 1 2 A. ​4 ​B. 10 ​C. 14 D. 37

14

For the following distribution of quiz scores, if a score of X = 3 or higher is needed for a passing grade, how many individuals passed?​ X f 5 6 4 5 3 5 2 3 1 2 Question 4 options: ​3 ​11 ​16 ​21

16

What is the median for the population of scores shown in the frequency distribution table?​ X f 5 1 4 2 3 3 2 4 1 2 Question 16 options: 2.5​​ 3 ​3.5 ​4

2.5

For the population of scores shown in the frequency distribution table, the mean is ____.​ ​ X f 5 2 4 1 3 3 2 2 1 2 ​ Question 3 options: ​15/5 = 3 ​15/10 = 1.50​ 29/5 = 5.80​ 29/10 = 2.90

29/10 = 2.90

What is the mode for the population of scores shown in the frequency distribution table?​ X f 5 1 4 2 3 3 2 4 1 2 Question 19 options: 2​​ 3 ​3.5 ​4

2​​

For the following distribution of quiz scores, How many individuals had a score of X = 2?​ X f 5 6 4 5 3 5 2 3 1 2 Question 5 options: ​1 ​2 ​3 ​5

3

For the following frequency distribution of exam scores, how many students had scores lower than X = 80?​ X f 90-94 3 85-89 4 80-84 5 75-79 2 70-74 1 Question 6 options: ​2 ​3 ​7 ​8

3

For the distribution in the accompanying graph, Figure 2.1, what is the value of ΣX? ​10 ​15 ​21 ​30

30

What is the mean for the population of scores shown in the frequency distribution table?​ X f 5 1 4 2 3 3 2 4 1 2​ Question 4 options: 15/5 = 3​​ 15/12 = 1.25 ​32/5 = 6.60​ 32/12 = 2.67

32/12 = 2.67

A population of N = 6 scores has ΣX = 30. What is the population mean?​ Question 2 options: 180​​ 30 ​15 5

5

For the following distribution, what is the width of each class interval?​ X f 20-24 2 5-19 5 10-14 4 5-9 1​ Question 10 options: 4​ ​4.5 ​5 ​10

5

What is the mean for the following sample of scores?​ Scores: 1, 4, 5, 10 Question 1 options:​ 20 ​10 ​5​ 4

5

A sample of n = 5 scores has a mean of M = 12. What is ΣX for this sample?​ Question 6 options:​ 12/5 = 2.40​ 5/12 = 0.417​ 5(12) = 60 ​52=25

5(12) = 60

What is the median for the following set of scores? Scores: 1, 2, 6, 11, 17​ Question 15 options:​ 4​ 6 ​8.5​ 8

6

What is the value of the median for the following set of scores? Scores: 1, 3, 4, 6, 7, 8, 12, 23​ Question 14 options:​ 6​ 6.5​ 7 ​8

6.5

For the following distribution, how many people had scores greater than X = 14?​ X f 20-25 2 15-19 5 10-14 4 5-9 1 Question 9 options: ​5 ​7 ​10 ​11

7

What is the highest score in the distribution for the scores shown in the accompanying stem and leaf display?​ 8| 314 7| 945 6| 7042 5| 68 4| 14 Question 26 options:​ 8 ​83​ 84​ 7042

84

A sample of n = 15 scores ranges from a high of X = 11 to a low of X = 3. If these scores are placed in a frequency distribution table, how many X values will be listed in the first column of that table? ​ A.8 ​B.9 ​C.11 ​D.15

9

One sample with n = 4 scores has a mean of M = 12, and a second sample with n = 6 scores has a mean of M = 8. If the two samples are combined, what is the weighted mean for the combined set of scores?​ Question 8 options: ​4.8 ​9.6 ​10.0 ​19.2

9.6

A researcher uses an anonymous survey to investigate the study habits of American college students. Based on the set of 56 surveys that were completed and returned, the researcher finds that these students spend an average of 4.1 hours each week working on course material outside of class. For this study, the set of 56 students who returned surveys is an example of__. A. parameter B. statistic C. population D. sample

D. Sample

A group of quiz scores ranges from 3 to 10, but no student had a score of X = 5. If the scores are put in a frequency distribution table, X = 5 would not be listed in the X column.​ Question options: True False

False

A grouped frequency distribution table does not provide enough information to obtain a complete listing of the original set of scores. Question 33 options: True False

False

A grouped frequency distribution table lists one interval as, 20-29. The width of this interval is 9 points. Question 30 options: True False

False

A recent report concluded that children with siblings have better social skills than children who grow up as an only child. This is an example of an experimental study.​ A. True B. False

False

A researcher interested in vocabulary development obtains a sample of three-year-old children to participate in a research study. The average score for the group of 20 is an example of a parameter.​ A. True B. False

False

A score equal to the 5th percentile is one of the highest scores in the distribution.​ Question 39 options: True False

False

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

False

Constructs are external attributes or characteristics that can be directly observed to describe and explain behavior.​ A. True B. False

False

For the following distribution of scores, 20% of the individuals have scores of X = 1.​ X f 5 2 4 8 3 5 2 3 1 2 Question 29 options: True False

False

If a set of exam scores forms a negatively skewed distribution, it suggests that the majority of the students did not score well on the exam.​ Question 38 options: True False

False

In a grouped frequency distribution table, one interval is identified as 30-34. This interval has a width of 5 points. Question 31 options: True False

False

The average score for a population is an example of a statistic. A. True B. False

False

The scores for a very easy exam would probably form a positively skewed distribution.​ Question 37 options: True False

False

There is a total of n = 5 scores in the distribution shown in the following table.​ X f 5 2 4 8 3 5 2 3 1 2 Question 28 options: True False

False

Using the average score to describe a sample is an example of inferential statistics.​ A. True B. False

False

Determining the class standing (1st, 2nd, and so on) for the graduating seniors at a high school would involve measurement on a(n) ____ scale of measurement.​ A. nominal ​B. ordinal C. ​interval D. ​ratio

Ordinal

Using letter grades (A, B, C, D, and E) to classify student performance on an exam is an example of measurement on a(n) ____ scale of measurement.​ A. nominal ​B. ordinal ​C. interval ​D. ratio

Ordinal

A researcher uses an anonymous survey to investigate the study habits of American college students. The Entire group of American college students is an example of a ___. ​A. sample ​B. statistic C. ​population ​D. parameter

Population

A researcher is interested in the eating behavior of rats and selects a group of 25 rats to be tested in a research study. The group of 25 rats is an example of a __. A. sample B. statistic C. population D. parameter

Sample

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. statistic; sample C. population; sample D. parameter; population

Sample; Population

A researcher records the change in weight (gain or lost) during the first semester of college for each individual in a group of 25 freshmen, and calculates the average change in weight. The average is an example of a ____.​ ​A. parameter ​B. statistic ​C. variable ​D. constant

Statistic

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. Statistical error B.​ inferential error C. ​sampling error D.​ parametric error

Statistical error

Which description provides an example of a continuous variable?​ A. The gender of each student in a psychology class ​B. The number of males in each class offered by the college ​C. The amount of time to solve a problem ​D. The number of children in a family

The amount of time to solve a problem

A sample has a mean of M = 86. If one new person is added to the sample, and ΣX is unchanged, what effect will the addition have on the sample mean? ​ Question 11 options:​ The sample mean will increase a little.​ The sample mean will decrease. ​The sample mean will remain the same.​ The sample mean will increase substantially.

The sample mean will decrease.

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

True

A correlational study typically uses only one group of participants but measures two different variables (two scores) for each individual.​ A. True B. False

True

A high school gym teacher records how much time each student requires to complete a one-mile run. This is an example of measuring a continuous variable.​ A. True B. False

True

A histogram is constructed so that adjacent bars touch.​ Question 35 options: 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. A. True B. 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.​ A. True B. False

True

For statistical purposes, there usually is not much difference between scores from an interval scale and scores from a ratio scale.​ A. True B. False

True

For the distribution in the following table, the percentile rank for X = 19.5 is 20%.​ X c% 25-29 100% 20-24 80% 15-19 20% Question 40 options: True False

True

For the following distribution, seven people have scores greater than X = 14.​ X f 20-24 2 15-19 5 10-14 4 5-9 1 Question 34 options: True False

True

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

True

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

True

If a set of scores covers a range of 80 points, the grouped frequency table should use an interval width of 8 points. Question 32 options: True False

True

Recording the number of students who are absent each day at a high school would be an example of measuring a discrete variable.​ A. True B. False

True

Students in an introductory art class are classified as art majors and non-art majors. This is an example of measurement on a nominal scale.​ A. True B. False

True

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

True

The normal distribution is an example of a symmetrical distribution. Question 36 options: True False

True

A recent study reports that elementary school students who were given a nutritious breakfast each morning had higher test scores than students who did not receive the breakfast. For this study, what is the independent variable?​A. The students who were given the nutritious breakfast ​B. The students who were not given the nutritious breakfast C. ​Whether or not a breakfast was given to the students ​D. The test scores for the students

Whether or not a breakfast was given to the students

For the distribution in the following table, what is the percentile rank for X = 8.5?​ X c% 9 100% 8 80% 7 50% 6 25% ​ Question 24 options: X = 90%​​ X = 80%​ X = 65%​ X = 50%

X = 80%​

In a frequency distribution graph, frequencies are presented on the ____ and the scores (categories) are listed on the ____.​ Question 11 options: ​X axis; Y axis ​horizontal line; vertical line ​Y axis; X axis ​class interval ;horizontal line

Y axis; X axis

In a research study comparing attitude scores for males and females, participant gender is an example of what kind of variable?​ ​A. an independent variable B. ​an dependent variable ​C. a quasi-independent variable ​D. a quasi-dependent variable

a quasi-independent variable

If a variable can be divided into an infinite number of fractional parts, then it is a(n) ____ variable.​ A. Independent ​B. dependent C. ​discrete ​D. continuous

continuous

For the following frequency distribution of quiz scores, how many individuals took the quiz?​ X f 5 6 4 5 3 5 2 3 1 2 ​ A.n=5 B.n=7 C.n=15 D.n=21

n = 21

The students in a psychology class seemed to think that the midterm exam was very easy. If they are correct, what is the most likely shape for the distribution of exam scores? Question 21 options:​ symmetrical​ positively skewed​ negatively skewed ​normal

negatively skewed

A researcher is curious about the average monthly cell phone bill for all high school students in the state of Florida. If this average could be obtained, it would be an example of a __. A. sample B. statistic C. population D. parameter

parameter

What term is used to describe the shape of a distribution in which the scores pile up on the left-hand side of the graph and taper off to the right?​ Question 19 options: ​symmetrical​ positively skewed ​negatively skewed ​normal

positively skewed

A researcher uses an anonymous survey to investigate the study habits of American college students. Based on the set of 56 surveys that were completed and returned, the researcher finds that these students spend an average of 4.1 hours each week working on course material outside of class. For this study, the average of 4.1 hours is an example of a __. A. Parameter ​B. statistic C. ​population ​D. sample

statistic

Statistical methods that organize, summarize, or streamline data are called ____. ​A. parameters ​B. statistics ​C. descriptive statistics ​D. inferential statistics

statistics

The normal distribution is ____.​ Question 18 Options: ​asymmetric ​skewed to the right ​skewed to the left ​symmetric

symmetric

In a distribution with positive skew, scores with the highest frequencies are ____.​ Question 22 options: ​on the right side of the distribution​on the left side of the distribution​in the middle of the distribution ​represented at two distinct peaks

the left side of the distribution​in

In a correlational study, ____.​ A. one variable is measured and two groups are compared ​B. two variables are measured and two groups are compared C. ​one variable is measured and there is only one group of participants ​D. two variables are measured and there is only one group of participants

two variables are measured and there is only one group of participants

In the simplest experimental study, ____.​ A. variable is measured and two groups are compared ​B. two variables are measured and two groups are compared ​C. one variable is measured and there is only one group of participants ​D. two variables are measured and there is only one group of participants

variable is measured and two groups are compared

A population has a mean of µ = 30. If 3 points are added to each score, what is the mean for the new distribution?​ Question 7 options: 3​​ 27 ​30 ​33

​33

In a grouped frequency distribution one interval is listed as 50-59. Assuming that the scores are measuring a continuous variable, what are the real limits of this interval? Question 7 options: ​50 and 59 ​50.5 and 59.5 ​49.5 and 59.5 ​49.5 and 60.5

​49.5 and 59.5

Which of the following statements is true for a distribution of data points?​ Question 17 options: ​75% of the data points are above the median. ​50% of the scores are above the median .​60% of the scores are below the median.​ 95% of the data points are above the median.

​50% of the scores are above the median

One sample has n = 4 scores and M = 10. A second sample has n = 6 scores and M = 5. If the two samples are combined, then what is the weighted mean for the combined sample?​ Question 12 options: ​70/4 = 17.5​ 70/6 = 11.7 ​70/10 = 7.0​ 10/5=2.0

​70/10 = 7.0​

In a population of N = 6, five of the individuals all have scores that are exactly 1 point above the mean. From this information, what can you determine about the score for the sixth individual?​ Question 13 options: ​It is also above the mean by 1 point. ​It is below the mean by 1 point. ​It is below the mean by 5 points. ​It is equal to the mean.

​It is below the mean by 5 points.

A population with a mean of µ = 6 has ΣX = 42. How many scores are in the population?​ Question 5 options:​ N = 6/42 = 1/7 ​N = 42/6 = 7​ N=42 ​N = 6*42 = 252

​N = 42/6 = 7​

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 amount of St. John's wort given to each participant ​B. The memory score for each participant ​C. The group of college students D. ​Whether or not they are full-time students

​The amount of St. John's wort given to each participant

Which description provides an example of a discrete variable?​ ​A. The time each student arrives in a psychology class B. ​The gender of each student in a psychology class ​C. The amount of time to solve a problem ​D. The amount of weight gained for each freshman at a local college

​The gender of each student in a psychology class

For the distribution in the following table, what is the 90th percentile?​ X c% 30-34 100% 25-29 90% 20-24 60% 15-19 20% ​ Question 25 options: X = 24.5​​ X = 25 ​X = 29 ​X = 29.5

​X = 29.5

What kind of frequency distribution graph shows the frequencies as bars that are separated by spaces? Question 16 options: ​a bar graph ​a histogram ​a polygon ​a pie chart

​a bar graph

What kind of frequency distribution graph shows the frequencies as bars, with no space between adjacent bars? ​a bar graph ​a histogram ​a polygon ​a pie chart

​a histogram

After measuring two individuals, a researcher can say that Tom's score is four points higher than Bill's. The measurements must come from a(n) ____ scale.​ A. ​nominal ​B. ordinal ​C. interval D. ​interval or ratio

​interval or ratio

What scale of measurement was used to measure the scores in the distribution shown in the accompanying graph, Figure 2.1? Question 14 options: ​nominal ​ordinal ​interval or ratio ​non-numeric

​interval or ratio

A sample has a mean of M = 40. If 10 points are added to one of the scores, what happens to the sample mean?​ Question 10 options: ​it is unchanged ​it increases ​it decreases a little ​it decreases substantially

​it increases

A distribution of scores has a mean of µ = 50. One new score is added to the distribution and the new mean is found to be µ = 48. From this result, you can conclude that the new score was ____.​ Question 9 options:​ greater than 50 ​less than 50 ​equal to 48​ between 50 and 52

​less than 50

A researcher measures eye color for a sample of n = 50 people. Which measure of central tendency would be appropriate to summarize the measurements?​ Question 20 options:​ mean ​median ​mode​ weighted mean

​mode​

If a frequency distribution is shown in a bar graph, what scale was used to measure the scores? Question 17 options: ​nominal ​nominal or ordinal ​ratio ​interval or ratio

​nominal or ordinal

What frequency distribution graph is appropriate for scores measured on a nominal scale? Question 12 options: ​only a histogram ​only a polygon ​either a histogram or a polygon ​only a bar graph

​only a bar graph

Determining a person's reaction time (in milliseconds) would involve measurement on a(n) ____ scale of measurement.​ A. nominal ​B. ordinal C. ​interval ​D. ratio

​ratio

In an experiment comparing two methods for teaching social skill training to children with autism, the independent variable is ____ and the dependent variable is ____.​ ​A. teaching methods; the autistic children ​B. the autistic children; the social skills that are learned ​C. the social skills that are learned; the autistic children ​D. teaching methods; the social skills that are learned

​teaching methods; the social skills that are learned