Deck 4: Describing Data: Displaying and Exploring Data

Question 1

Quartiles are another way to describe the central location of a distribution.

Answer 1

False

Question 2

A percentile can be a decile,but a decile cannot be a quartile.

Answer 2

True

Question 3

Quartiles divide a distribution into ten equal parts.

Answer 3

False

Question 4

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.

Question 5

A student scored in the 65^th percentile on a standardized test.This means that the student scored higher than 65% of all students who took the test.

Question 6

A scatter diagram is useful for quickly graphing frequencies in a small data set.

Question 7

A dot plot shows the relative symmetry of a distribution.

Question 8

A dot plot and a scatter diagram are different names for the same graph.

Question 9

Quartiles are another way to describe the dispersion of a distribution.

Question 10

A dot plot is useful for showing the mode of a distribution.

Question 11

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

Question 12

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

Question 13

Percentiles divide a distribution into one hundred equal parts.

Question 14

Quartiles divide a distribution into four equal parts.

Question 15

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

Question 16

The 50^th percentile of a distribution is the same as the distribution's median.

Question 17

A dot plot shows the quartiles of a distribution.

Question 18

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

Question 19

A dot plot is useful for showing the possible outliers.

Question 20

A scatter diagram is an easy way to represent the relationship between two variables.

Question 21

In a negatively skewed distribution,the mean is smaller than the median or mode and the mode occurs at the peak of the curve.

Question 22

Negatively skewed indicates that a distribution is not symmetrical.The long tail is to the left.

Question 23

A box plot provides the information necessary to compute the Pearson's coefficient of skewness.

Question 24

In a box plot,if a value is more than 1.5 times the standard deviation from the first or third quartile,the value is an outlier.

Question 25

The coefficient of skewness is computed by dividing the standard deviation by the median and multiplying the quotient by 100.

Question 26

A box plot graphically shows data that are in percentiles.

Question 27

The coefficient of skewness is useful for comparing distributions with different units.

Question 28

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

Question 29

The coefficient of skewness measures the symmetry of a distribution based on the standard deviation as a percent of the mean.

Question 30

A box plot shows the relative symmetry of a distribution.

Question 31

A quartile can be a decile,but a decile cannot be a percentile.

Question 32

A box plot shows a distribution's mean and mode.

Question 33

A box plot shows the range of values that correspond to the upper 25% of the distribution.

Question 34

The interquartile range is the difference between the values of the first and third quartile,indicating the range of the middle fifty percent of the observations.

Question 35

The coefficient of skewness is function of the (summed deviations from the mean)raised to the 3^rd power.

Question 36

For a distribution,the 2^nd quartile,the 5^th decile,and the 50^th percentile,are the same as the median.

Question 37

An outlier is a value in a data set that is inconsistent with the rest of the data.

Question 38

In a box plot,if a value is more than 1.5 times the interquartile range from the first or third quartile,the value is an outlier.

Question 39

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

Question 40

In a box plot,outliers are shown in the first quartile.

Question 41

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.

Question 42

A box plot of sales versus production may be constructed by plotting the data on a graph labeled with sales on the Y-axis and production on the X-axis.

Question 43

What does the interquartile range describe?

A)The lower 50% of the observations
B)The middle 50% of the observations
C)The upper 50% of the observations
D)The lower 25% and the upper 25% of the observations

Question 44

A sample of experienced typists revealed that their mean typing speed is 87 words per minute and the median is 73.The standard deviation is 16.9 words per minute.What is the Pearson's coefficient of skewness?

A)-2.5
B)-4.2
C)+4.2
D)+2.5

Question 45

If Pearson's coefficient of skewness is negative,then the mean is greater than the median.

Question 46

If Pearson's coefficient of skewness is negative,then the distribution is skewed to the right.

Question 47

A scatter diagram of sales versus production may be constructed by plotting the data on a graph labeled with sales on the Y-axis and production on the X-axis.

Question 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

Question 49

If Pearson's coefficient of skewness is negative,then the distribution is skewed to the left.

Question 50

A relationship between gender and preference for Coke or Pepsi can be best represented by a dot plot.

Question 51

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

Question 52

A relationship between gender and preference for Coke or Pepsi can be best represented by a contingency table.

Question 53

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 the Pearson's coefficient of skewness?

A)-1.00
B)-0.75
C)+0.75
D)+1.00

Question 54

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%

Question 55

What is the value of the Pearson coefficient of skewness for a distribution with a mean of 17,median of 12 and standard deviation of 6?

A)+2.5
B)-2.5
C)+0.83
D)-0.83

Question 56

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

Question 57

If Pearson's coefficient of skewness is equal to 0,then the mean and median are equal.

Question 58

A relationship between gender and preference for Coke or Pepsi can be best represented by a scatter diagram.

Question 59

What statistics are needed to draw a box plot?

A)Minimum,maximum,median,first and third quartiles.
B)Median,mean and standard deviation.
C)A median and an interquartile range.
D)A mean and a standard deviation.

Question 60

A box plot shows

A)The mean and variance
B)The relative symmetry of a distribution for a set of data
C)The percentiles of a distribution
D)The deciles of a distribution

Question 61

What is the best way to display the relationship between two variables measured on an interval or ratio level? __________.

Question 62

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.

Question 63

A study of the net sales of a sample of small corporations revealed that the mean net sales is $2.1 million,the median $2.4 million,the modal sales $2.6 million and the standard deviation of the distribution is $500,000.What is the Pearson's coefficient of skewness?

A)-9.1
B)+6.3
C)-3.9
D)+2.4
E)None of the above

Question 64

The percentile range is the distance between any two ____________.

Question 65

In a positively skewed distribution,where is the 99^th percentile located? _______________

Question 66

In a negatively skewed distribution,where is the 1^st percentile located? _______________

Question 67

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.

Question 68

What statistic can be used to measure the relative symmetry of a distribution? ___________________________________

Question 69

A telemarketing firm is monitoring the performance of its employees based on the number of sales per hour.One employee had the following sales for the last 20 hours. For the distribution of number of sales per hour,50% are greater than ____________.

Question 70

In a symmetric distribution,where is the 99^th percentile located? _______________

Question 71

What unit of measurement is used to express the coefficient of skewness? _________

Question 72

A telemarketing firm is monitoring the performance of its employees based on the number of sales per hour.One employee had the following sales for the last 20 hours. What is the median for the distribution of number of sales per hour? ____________

Question 73

The coefficient of skewness is a measure of ____________.

Question 74

The Pearson's coefficient of skewness (Sk)measures the amount of skewness and may range from -3.0 to +3.0.It is computed by subtracting the median from the mean,multiplying the result by 3 and dividing by ________________.

Question 75

A telemarketing firm is monitoring the performance of its employees based on the number of sales per hour.One employee had the following sales for the last 20 hours. What is the first quartile for the distribution of number of sales per hour? ________________

Question 76

Given the sample information in the following table regarding public opinion on gun control,who is more likely to favor gun control?

Question 77

What chart or graph is useful for illustrating frequencies? ____________________.

Question 78

For a set of data,how many quartiles are there? _____

Question 79

If the mean of a distribution is smaller than the median and mode,what is the sign of Pearson's coefficient of skewness? _______________

Question 80

A telemarketing firm is monitoring the performance of its employees based on the number of sales per hour.One employee had the following sales for the last 20 hours. What is the third quartile for the distribution of number of sales per hour? _____________