Deck 14: Descriptive Statistics

Question 1

What kind of graph uses bars that are separated by spaces?

A) a bar graph
B) a histogram
C) both a and b
D) neither a nor b

Answer 1

A

Question 2

A is a systematic arrangement of data values in which the unique data values are rank ordered and the frequencies are provided for each of these values.

A) scatter plot
B) frequency distribution
C) line graph
D) mean plot

Answer 2

B

Question 3

SPSS is

A) measure of effect size.
B) a method of randomly selecting participants from a population.
C) a statistical software package commonly used by psychologists.
D) used for descriptive statistics but not inferential statistics.

Answer 3

C

Question 4

The type of graph that would best display an interaction effect is:

A) pie graph.
B) histogram.
C) scatterplot.
D) line graph

Question 5

Use the following frequency distribution to answer questions

Which of the following is the lowest score in the frequency distribution?

A) 23
B) 10
C) 20
D) 25

Question 6

When drawing a line graph, the dependent variable normally belongs on

A) the horizontal axis.
B) the vertical axis.
C) either the horizontal or vertical axis.
D) horizontal axis unless the variable is nominal.

Question 7

A correlation coefficient is used to:

A) examine the relationship between two quantitative variables
B) examine the relationship between three categorical variables
C) make a statement of causation in nonexperimental research
D) establish the time ordering of variables n.

Question 8

Use the following frequency distribution to answer questions

What is the most frequently occurring score in the frequency distribution?

A) 23
B) 10
C) 20
D) 25

Question 9

The relationship between number of friends and happiness is weaker in adulthood than in childhood. You make a scatter plot for children and a scatter plot for adults. In each scatter plot, you have SPSS insert the best fitting straight line. The cluster of dots for adults compared to that for children):

A) will be less spread out surrounding the best fitting straight line i.e., they will be closer to the line).
B) will be more spread out surrounding the best fitting straight line.
C) all dots will always fall on the straight line.
D) there will be a lack any apparent tilt in the line.

Question 10

Use the following frequency distribution to answer questions

Which of the following graphs is most appropriate when displaying categorical data?

A) scatterplot
B) bar graph
C) histogram
D) any of the above

Question 11

Use the following frequency distribution to answer questions

Which of the following ACT scores is the mode for the data shown in the frequency distribution?

A) 23
B) 10
C) 20
D) 25

Question 12

Inferential statistics involve the use of to draw conclusions about .

A) populations; samples
B) samples; populations
C) data sets; descriptive statistics
D) z scores; normal distributions

Question 13

The use of descriptive statistics involves

A) summarizing your data so that it is easier for others to understand.
B) making inferences from your data to a population.
C) the use of both point and interval estimation.
D) hypothesis testing.

Question 14

What type of graph would be appropriate to display the frequency table of cat ownership shown below?

A) bar graph
B) histogram
C) scatterplot
D) line graph

Question 15

Use the following frequency distribution to answer questions

An ACT score of 22 made up what percentage of cases in the frequency distribution?

A) 10
B) 15
C) 20
D) 30

Question 16

What kind of graph is used to display frequencies as bars without spaces between them?

A) a bar graph
B) a histogram
C) a scatterplot
D) all of the above

Question 17

Use the following frequency distribution to answer questions

Dr. Gomez would like to graph the scores from a recent exam a quantitative variable), what type of graph should she use and what should be on the horizontal axis?

A) pie chart; modal values
B) histogram; exam score values
C) bar graph; frequency values
D) bar graph; exam scores

Question 18

Elizabeth wants to graph the relation between the number of hours spent studying and major psychology, biology, education, etc.). What type of graph should she use?

A) line graph
B) scatterplot
C) bar graph
D) frequency polygon

Question 19

Use the following frequency distribution to answer questions

What ACT score occurred 20% of the time?

A) 20
B) 30
C) 4
D) 22

Question 20

In a histogram, frequencies are presented on the and the score variable is presented on the .

A) vertical axis; horizontal axis
B) horizontal axis; vertical axis
C) either axis; either axis
D)-axis; Y-axis

Question 21

What is the median for the following set of scores? 2, 6, 2, 11, 14

A) 2
B) 4 :
C) 6
D) 8.5

Question 22

If we were interested in predicting grade point average from the number of hours students spend on the internet what should we place on the vertical axis?

A) grade point average
B) number of hours on the internet
C) students
D) either variable

Question 23

After taking 23, 5-point, quizzes during the semester, both Jabari and Elaine have an average quiz score of 4.00. However, the standard deviation of Jabari's scores was .76 and Elaine's standard deviation was .25. What does it mean that Jabari and Elaine had the same quiz average but very different standard deviations?

A) Jabari was above the class average but Elaine was below the class mean
B) Jabari was more consistent than Elaine
C) Elaine's individual quiz scores were closer to her average while Jabari's scores were more variable
D) Jabari performed better than Elaine

Question 24

What is the median for the following set of scores? 1, 3, 3, 5, 8, 10

A) 3
B) 4
C) 5
D) 6

Question 25

The least informative measure of central tendency is the

A) mode.
B) median.
C) range.
D) variance.

Question 26

For her senior research project Jerri collects survey data on the number of hours spent on social networking and grade point average GPA). She creates a scatterplot to graph her results. If the pattern of dots on her scatterplot goes from lower left to upper right, what would this indicate?

A) that the relationship is strong
B) that it is a positive relationship
C) that it is a negative relationship
D) that people who spend a lot of time social networking tend to have a lower GPA

Question 27

A raw score above the mean of the distribution will result in a z score

A) greater than zero
B) of zero
C) less than zero
D) equal to the mean of the distribution

Question 28

What is the mode for the following sample of n = 8 scores? Scores: 0, 0, 1, 2, 2, 2, 2, 3

A) 2
B) 2.5
C) 12/8 = 1.50
D) 12

Question 29

A z score of 1.00 is located:

A) one standard deviation below the mean.
B) below the mean but we cannot tell how far below.
C) above the mean but we cannot tell how far above.
D) one standard deviation above the mean.

Question 30

is the exact average deviation of data values from the mean in squared units, and is the approximate average deviation of data values from the mean in regular units.

A) Standard deviation; variance
B) Effect size; correlation
C) Variance; standard deviation
D) Negative correlation; positive correlation

Question 31

What is the relationship between the standard deviation and variance?

A) standard deviation equals squared variance
B) variance is the square root of standard deviation
C) standard deviation is the square root of variance
D) these two measures are unrelated

Question 32

The mean of a set of numbers converted to z scores is and the standard deviation is .

A) 0; 1
B) 1; 0
C) 2; 1
D) equal to population mean; impossible to determine

Question 33

The statistical symbol for a sample mean is

A) μ
B) α
C) X
D) Σ

Question 34

What is Σ X for the following group of scores? 1, 2, 3, 4, 5

A) 3
B) 5
C) 15
D) 30

Question 35

If the pattern of dots on a scatterplot runs from upper left to lower right what does this indicate?

A) that the relationship is strong
B) that the relationship is weak
C) that it is a positive relationship
D) that it is a negative relationship

Question 36

To display the relationship between two quantitative variables, one should use

A) a bar graph.
B) a histogram.
C) a scatterplot.
D) z scores.

Question 37

A sample consists of n = 25 scores. How many of the scores are used to calculate the range?

A) 0
B) 2
C) 5
D) 25

Question 38

What is the mean for the following sample of scores? 2, 4, 6, 8

A) 20
B) 10
C) 5
D) 4

Question 39

Which set of scores has the smallest standard deviation no calculations allowed or needed)?

A) 11, 17, 31, 53
B) 5, 11, 42, 22
C) 155, 153, 155, 157
D)27, 105, 10, 80

Question 40

The mean, median, and mode are all considered to be measures of

A) inferential statistics.
B) effect size.
C) variability.
D) central tendency.

Question 41

Research has indicated that there is a curvilinear relationship between the number of drinks a person has per day and their likelihood of developing heart disease. Calculating a regular correlation coefficient on these data would likely result in

A) an artificially low value.
B) a value close to +1.00.
C) a value close to -1.00.
D) a value larger than 1.00.

Question 42

A positive value for a correlation indicates

A) increases in one variable tend to be accompanied by increases in the second variable.
B) increases in one variable tend to be accompanied by decreases in the second variable.
C) a stronger relationship than if the correlation were negative.
D) nothing; all correlation values are positive.

Question 43

The absolute value of a correlation coefficient indicates the of the relationship and the sign indicates the of the relationship.

A) causality; magnitude
B) direction; causality
C) strength; direction
D) strength; whether or not a relationship exists

Question 44

For a data set with a mean = 10 and standard deviation = 2, what is the z score corresponding to a raw score of 7?

A) +1.5
B) -1.5
C) 2
D) -2

Question 45

When calculating a correlation coefficient, can only be used when the data are related in a linear fashion.

A) Cohen's d
B) Pearson's correlation
C) z score
D) F test

Question 46

How does multiple regression differ from simple regression?

A) it contains multiple data points
B) it involves multiple dependent variables
C) it includes multiple independent/predictor variables
D) it can always be used to establish causality

Question 47

An effect size is a measure of

A) the magnitude of the relationship between two variables.
B) whether the result reached statistical significance.
C) the validity of our result.
D) the probability that we made a correct decision.

Question 48

A perfect relationship will results in a correlation coefficient value of

A) 1.00.
B) -1.00.
C) both a and b
D) neither a nor b

Question 49

Assume that the correlation coefficient between class attendance and number of problems missed on an exam is -.77). Which of the following statements regarding this finding is correct?

A) students who had fewer absences answered more questions correctly
B) students who had more absences answered more questions correctly
C) a negative correlation value is impossible; there must be a mistake in the calculations
D) the number of problems answered correctly is below the class mean

Question 50

Which of the following is a measure of the standardized difference between two means?

A) Cohen's d
B)-bar
C) SD
D) Σr

Question 51

Assume that within one study the regression equation relating daily saturated fat intake in grams x) to blood cholesterol level y) is Y-hat = 130 + 5X. What is the value of the y-intercept for this problem?

A) 1
B) 5
C) 130
D) impossible to determine

Question 52

In a normal distribution, the percentage of raw scores falling within one standard deviation of the mean equals

A) 34.11%.
B) 68.26%.
C) 95.44%.
D) 99.74%.

Question 53

What position in a distribution of numbers corresponds to a z score of z = -2.00?

A) two standard deviation units above the mean
B) two points above the mean
C) two standard deviation units below the mean
D) two points below the mean

Question 54

What is the median of these numbers: 2, 7, 6, 8, 10 ?

A) 7
B) 6
C) 8
D) 10

Question 55

The amount of change in Y for every one unit increase in X is indicated by the

A) magnitude of the correlation coefficient.
B) correlation coefficient sign.
C) y-intercept.
D) slope regression coefficient).

Question 56

Vanessa Kanaan, an Associate Professor at the University of Louisville, creates a new "empathy" test and administers it to business majors and biology majors. She finds that the two groups differ significantly from each other with an effect size Cohen's d) equal to .85. Based on this information which of the following statements is accurate?

A) although her results are statistically significant, the effect size would be considered "small" meaning that it has little practical importance
B) the effect size in this study would be considered "moderate"
C) the effect size in this study would be considered "large"
D) it is impossible to obtain an effect size of .85; she must have calculated it incorrectly

Question 57

The normal distribution follows within rounding) which of the following rules?

A) the symmetrical rule
B) the central limit theorem
C) the 68, 95, 99.7 rule
D) the normal distribution rule

Question 58

Dr. Wilson conducts an experiment and finds that the difference between the experimental and control group means is 45.3 units. This can be referred to as the

A) effect size indicator
B) unstandardized difference between means
C) standardized difference between means
D) z score

Question 59

Professor Ganji jokes that there is a -.85 correlation between the number of courses a student takes with him and the student's grade point average. Which of the following is the best interpretation of this statement?

A) in general, the more courses that students take from professor Ganji the lower their grade point average
B) the more courses students take from professor Ganji the higher their grade point average
C) professor Ganji is an easy instructor
D) students who take more of professor Ganji's class are guaranteed to have a higher grade point average

Question 60

Which correlation coefficient represents the strongest association between X and Y?

A) +.20
B) +.60
C) -.80
D) -1.5

Question 61

The regression coefficient in a multiple regression equation is called

A) partial correlation coefficient
B) correlation coefficient
C) partial regression coefficient
D) simple regression coefficient

Question 62

An) coefficient predicts the change in a dependent variable given a one unit change in the independent variable.

A) regression
B) correlation
C) ANOVA
D) ANCOVA

Question 63

If you would like to display the relationship between two categorical variables you should use a

A) bar graph.
B) contingency table.
C) scatterplot.
D) histogram.

Question 64

Partial correlation

A) is calculated when you have incomplete data.
B) allows the researcher to control for the influence of one or more variables.
C) is less useful than complete correlation.
D) allows the researcher to make strong cause and effect statements when based on nonexperimental data .

Question 65

regression involves the use of only one independent or predictor variable while regression involves two or more independent or predictor variable.

A) Pearson's; partial
B) Easy; hard
C) Simple; multiple
D) Alpha; omega

Question 66

Assume that within one study the regression equation relating daily saturated fat intake in grams x) to blood cholesterol level y) is Y-hat = 130 + 5X. What is the value of the regression coefficient?

A) 1
B) 5
C) 130
D) impossible to determine