# Quiz 4: Describing Data: Displaying and Exploring Data

Statistics

64

All Questions

41

Multiple Choice

23

True False

0

Essay

0

Short Answer

0

Not Answered

Q 1

A dot plot is an easy way to represent the relationship between two variables.

Free

True False

False

Q 2

A dot plot is useful for quickly graphing frequencies in a small data set.

Free

True False

True

Q 3

A dot plot shows the symmetry of a distribution.

Free

True False

True

Q 4

A dot plot is useful for showing individual observations.

True False

Q 5

A dot plot is useful for showing the range of the data.

True False

Q 6

Quartiles divide a distribution into four equal parts.

True False

Q 7

Quartiles divide a distribution into 10 equal parts.

True False

Q 8

Percentiles divide a distribution into 100 equal parts.

True False

Q 9

A student scored in the 85

^{th}percentile on a standardized test. This means that the student scored lower than 85% of all students who took the test. True False

Q 10

The 50th percentile of a distribution is the same as the distribution mean.

True False

Q 11

A box plot graphically shows the 10th and 90th percentiles.

True False

Q 12

The "box" in a box plot shows the interquartile range.

True False

Q 13

A box plot shows the skewness of a distribution.

True False

Q 14

The coefficient of skewness is the standard deviation divided by the mean.

True False

Q 15

Pearson's coefficient of skewness is a measure of a distribution's symmetry.

True False

Q 16

If a distribution is negatively skewed,the distribution is not symmetrical and the long tail is to the left.

True False

Q 17

A scatter diagram of sales versus production is labeled with sales on the Y-axis and production on the X-axis.

True False

Q 18

A scatter diagram of sales versus production may be constructed by plotting the minimum,first quartile,median,third quartile,and maximum values of each variable.

True False

Q 19

A scatter diagram is used to illustrate a relationship between gender and the preference for Coke or Pepsi.

True False

Q 20

A relationship between two nominal variables is summarized by a contingency table.

True False

Q 21

A stem-and-leaf diagram shows the actual data values.

True False

Q 22

In a stem-and-leaf display,the leaf represents a class of a frequency distribution.

True False

Q 23

In a stem-and-leaf display,the leaf represents the members of a class in a frequency distribution.

True False

Q 24

A dot plot shows ________.
A)the general shape of a distribution
B)the mean,median,and mode
C)the relationship between two variables
D)the interquartile range

Multiple Choice

Q 25

A dot plot is best applied when ________.
A)the mean,median,and mode are equal
B)the general shape of a distribution is symmetric
C)the relationship between two variables is summarized
D)a single variable is summarized

Multiple Choice

Q 26

A dot plot is best applied for a data set with ________.
A)1,000 observations
B)50 observations
C)more than one variable
D)one mode

Multiple Choice

Q 27

A dot plot can be used to show ________.
A)the mean,median,and mode
B)the general shape of a distribution for a nominal qualitative variable
C)the distribution for a quantitative variable
D)the interquartile range

Multiple Choice

Q 28

The following graph is a ________.
A)Dot plot
B)Stem-and-leaf diagram
C)Box plot
D)Contingency table

Multiple Choice

Q 29

The test scores for a class of 147 students are computed. What is the location of the test score associated with the third quartile?
A)111
B)37
C)74
D)75%

Multiple Choice

Q 30

Quartiles divide a distribution into ________.
A)2 equal parts
B)4 equal parts
C)10 equal parts
D)100 equal parts

Multiple Choice

Q 31

In a distribution,the second quartile corresponds with the ________.
A)mean
B)median
C)mode
D)variance

Multiple Choice

Q 32

Percentiles divide a distribution into ________.
A)2 equal parts
B)4 equal parts
C)10 equal parts
D)100 equal parts

Multiple Choice

Q 33

To locate the percentile for a given observation in a data set,the data must be ________.
A)sorted and listed from the minimum to the maximum values
B)displayed in a histogram
C)summarized in a frequency distribution
D)distributed symmetrically around the mean

Multiple Choice

Q 34

If a student places in the 99th percentile on an exam,she performed better than 99% of all students who completed the exam. Her performance is similar to a statement based on a ________.
A)frequency table
B)cumulative frequency distribution
C)histogram
D)pie chart

Multiple Choice

Q 35

In the following set of data: (1,3,5,6,7,9,100),what are the first,second,and third quartiles?
A)1,6,and 100
B)3,5,and 9
C)3,6,and 9
D)1,5,and 100

Multiple Choice

Q 36

The following graph is a ________.
A)dot plot
B)stem-and-leaf display
C)box plot
D)contingency table

Multiple Choice

Q 37

What statistics are needed to draw a box plot?
A)The minimum,maximum,median,first and third quartiles
B)The median,mean,and standard deviation
C)The median and interquartile range
D)The mean and standard deviation

Multiple Choice

Q 38

A box plot shows ________.
A)the mean and variance
B)the relative symmetry of a distribution for a set of data
C)the 10th and 90th percentiles of a distribution
D)the deciles of a distribution

Multiple Choice

Q 39

What does the interquartile range describe?
A)The range of the lower 50% of the observations
B)The range of the middle 50% of the observations
C)The range of the upper 50% of the observations
D)The ranges of the lower 25% and the upper 25% of the observations

Multiple Choice

Q 40

The interquartile range is graphically presented in a ________.
A)dot plot
B)stem-and-leaf display
C)box plot
D)contingency table

Multiple Choice

Q 41

Outliers are clearly presented in a ________.
A)dot plot
B)stem-and-leaf display
C)box plot
D)contingency table

Multiple Choice

Q 42

Using the following statistics to describe a distribution of data,what is the interquartile range? Minimum = 10
Q1 = 25
Median = 50
Q3 = 75
Maximum = 95
A)85
B)50
C)15
D)20

Multiple Choice

Q 43

If the coefficient of skewness is equal to zero,the shape of the distribution is ________.
A)negatively skewed
B)symmetric
C)positively skewed
D)unknown

Multiple Choice

Q 44

The range of the coefficient of skewness is ________.
A)values greater than or equal to zero or always positive
B)values less than or equal to zero or always negative
C)both positive and negative values
D)values between −1 and +1

Multiple Choice

Q 45

The following graph is ________.
A)positively skewed
B)negatively skewed
C)symmetric
D)uniformly distributed

Multiple Choice

Q 46

A large oil company is studying the number of gallons of gasoline purchased per customer at self-service pumps. The mean number of gallons is 10.0,with a standard deviation of 3.0 gallons. The median is 10.75 gallons. What is Pearson's coefficient of skewness in this instance?
A)−1.00
B)−0.75
C)+0.75
D)+1.00

Multiple Choice

Q 47

What is the value of the Pearson coefficient of skewness for a distribution with a mean of 17,a median of 12,and a standard deviation of 6?
A)+2.5
B)−2.5
C)+0.83
D)−0.83

Multiple Choice

Q 48

What is the possible range of values for Pearson's coefficient of skewness?
A)−1 and +1
B)−3 and +3
C)0% and 100%
D)Unlimited values

Multiple Choice

Q 49

A sample of experienced typists revealed that their mean typing speed is 87 words per minute and the median typing speed is 73 words per minute. The standard deviation of typing speed is 16.9 words per minute. What is the Pearson coefficient of skewness?
A)−2.5
B)−4.2
C)+4.2
D)+2.5

Multiple Choice

Q 50

The following graph is a ________.
A)dot plot
B)stem-and-leaf display
C)box plot
D)scatter diagram

Multiple Choice

Q 51

The following graph illustrates ________.
A)a positive or direct relationship
B)a negative or inverse relationship
C)no relationship
D)a distribution for a single variable

Multiple Choice

Q 52

In a scatter diagram,we describe the relationship between ________.
A)two variables measured at the ordinal level
B)two variables,one measured as an ordinal variable and the other as a ratio variable
C)two variables measured at the interval or ratio level
D)a variable measure on the interval or ratio level and time

Multiple Choice

Q 53

In a contingency table,we describe the relationship between ________.
A)two variables measured at the ordinal or nominal level
B)two variables,one measured as an ordinal variable and the other as a ratio variable
C)two variables measured at the interval or ratio level
D)a variable measure on the interval or ratio level and time

Multiple Choice

Q 54

A contingency table would be used to summarize data such as ________.
A)company employees by gender and organizational title
B)company employees by gender and age
C)company employees by compensation and age
D)company employees by compensation and years with the company

Multiple Choice

Q 55

A stem-and-leaf display includes the following row: 3 | 0 1 3 5 7 9. Assume that the data are rounded to the nearest whole number. Which of the following statements is true?
A)The frequency of the class is 7.
B)The minimum value in the class is 0.
C)The maximum value in the class is 39.
D)The class interval is 5.

Multiple Choice

Q 56

The following table is a ________.
A)dot plot
B)stem-and-leaf display
C)box plot
D)contingency table

Multiple Choice

Q 57

A stem-and-leaf display includes the following row: 5 | 10 11 31 52 79 98. Assume that the data are rounded to the nearest whole number.
A)The frequency of the class is 7.
B)The minimum value in the class is 5.
C)The maximum value in the class is 98.
D)The class interval is 100.

Multiple Choice

Q 58

In the following table,
A)the median is 2.5.
B)the minimum value is 135.
C)the maximum value is 456.
D)the range is 33.

Multiple Choice

Q 59

In the following table,
A)there are 16 observations.
B)there are 4 observations in the second class.
C)there are 10 observations less than 30.
D)there are 10 observations greater than 30.

Multiple Choice

Q 60

The median of a sample will always equal the ________.
A)mode
B)mean
C)50th percentile
D)All of these answers are correct.

Multiple Choice

Q 61

The 75th percentile is referred to as the ________.
A)first quartile
B)second quartile
C)third quartile
D)fourth quartile

Multiple Choice

Q 62

The 67th percentile is ________.
A)the value above which 67% of the observations occur
B)a value one less than 67% of the observations
C)the value below which 67% of the observations occur
D)the value of the observation at the 67th location

Multiple Choice

Q 63

The eighth decile ________.
A)contains at least 70% of the observations
B)is the same as the 40th percentile
C)is the same as the 70th percentile
D)is the same as the 80th percentile

Multiple Choice

Q 64

Which of the following is NOT a measure of dispersion?
A)The interquartile range
B)The standard deviation
C)The 50th percentile
D)The range

Multiple Choice