# Bstat chapter 2

question

A stem-and-leaf display is a graphical portrayal of a data set that shows the data set’s overall pattern of variation.

true
question

The relative frequency is the frequency of a class divided by the total number of measurements.

true
question

A bar chart is a graphic that can be used to depict qualitative data

true
question

Stem-and-leaf displays and dot plots are useful for detecting outliers.

true
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A scatter plot can be used to identify outliers.

false
question

When looking at the shape of the distribution using a stem-and-leaf, a distribution is skewed to the right when the left tail is shorter than the right tail.

true
question

When we wish to summarize the proportion (or fraction) of items in a class we use the frequency distribution for each class.

false
question

When establishing the classes for a frequency table it is generally agreed that the more classes you use the better your frequency table will be.

false
question

The sample cumulative distribution function is non-decreasing.

true
question

A frequency table includes row and column percentages.

false
question

A(n) ______ is a graph of a cumulative distribution.

Ogive plot
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________ can be used to study the relationship between two variables.

Crosstabulation tables
question

Row or column percentages can be found in:

Crosstabulation tables
question

All of the following are used to describe quantitative data except the

pie chart
question

An observation separated from the rest of the data is a(n)

outlier
question

Which of the following graphs is for qualitative data?

Bar Chart
question

A Stem and Leaf display is best used to

Display the shape of the distribution.
question

When grouping a large sample of items into classes, the ______________ is a better tool than the ___________.

Histogram, stem and leaf display
question

A ______________ displays the frequency of each group with qualitative data and a ____________ displays the frequency of each group with quantitative data.

Bar chart, histogram
question

A ______________ shows the relationship between two variables

Scatter Plot
question

A ______________ can be used to differentiate the \”vital few\” causes of quality problems from the \”trivial many\” causes of quality problems.

Pareto chart
question

______________ and _____________ are used to describe qualitative (categorical) data.

Bar charts, pie charts
question

Which one of the following statistical tools is used with quantitative data?

Histogram
question

When developing a frequency distribution the class (group), intervals should be

mutually exclusive.
question

Which of the following graphical tools is not used to study the shapes of distributions?

Scatter plot
question

All of the following are used to describe qualitative data except the:

Histogram
question

If there are 130 values in a data set, how many classes should be created for a frequency histogram?

8
question

If there are 120 values in a data set, how many classes should be created for a frequency histogram?

7
question

If there are 62 values in a data set, how many classes should be created for a frequency histogram?

6
question

If there are 30 values in a data set, how many classes should be created for a frequency histogram?

5
question

A CFO is looking at how much of a company’s resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf

Skewed to the right
question

A CFO is looking at how much of a company’s resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf

5.2
question

A CFO is looking at how much of a company’s resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf If a frequency histogram were to be created using these data, how many classes would you create?

6
question

A CFO is looking at how much of a company’s resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf What would be the class length that would be used in creating a frequency histogram?

1.4
question

A CFO is looking at how much of a company’s resources are spent on computing. He samples companies in the pharmaceutical industry and developed the following stem-and-leaf

5.2 – 6.4
question

The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below: How many flights were used in this plo

12
question

The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below: In developing a histogram of these data, how many classes would be used?

4
question

The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below: What would be the class length for creating the frequency histogram?

1.7
question

A company collected the ages from a random sample of its middle managers with the resulting frequency distribution shown below: What would be the approximate shape of the relative frequency histogram?

Skewed to the left
question

A company collected the ages from a random sample of its middle managers with the resulting frequency distribution shown below: What is the relative frequency for the largest interval?

.283
question

A company collected the ages from a random sample of its middle managers with the resulting frequency distribution shown below: What is the midpoint of the third class interval?

32.5
question

The 550 students answered an additional question with the following results based on their rating of their instructor: What proportion of the students who rated their instructor as very or somewhat effective received a B or better in the class?

0.898
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The 550 students answered an additional question with the following results based on their rating of their instructor: What proportion of all 550 students received less than a C?

0.08
question

822 customers were randomly selected from those who had recently bought a book over the internet. The chart below shows the breakdown of the classification of the book What percentage of the books purchased were either mystery or science fiction/fantasy?

36.5
question

822 customers were randomly selected from those who had recently bought a book over the internet. The chart below shows the breakdown of the classification of the book type: What percentage of the books purchased were self-help books?

11.44%
question

822 customers were randomly selected from those who had recently bought a book over the internet. The chart below shows the breakdown of the classification of the book type: What percentages of books were in the top two categories?

43.43
question

A graphical display of categorical data made up of vertical or horizontal bars is called a _____.

bar chart
question

A flaw possessed by a population or sample unit is _____

defect
question

A graphical portrayal of a data set that divides the data into classes and gives the frequency of each class is a(n) _____.

Histogram
question

The number of measurements falling within a class interval is called the _____

Frequency
question

A relative frequency curve having a long tail to the right is said to be _____.

Skewed to the right
question

The percentage of measurements in a class is called the _____ of that class

relative frequency
question

A histogram that tails out towards larger values is _____

skewed to the right
question

A histogram that tails out towards smaller values is _____

skewed to left
question

A(n) ___________ is a graphical display of categorical data made up of vertical or horizontal bars.

bar chart
question

A __________ can be used to differential the \”vital few\” causes of quality problems from the \”trivial many\” causes of quality problems.

Pareto chart
question

A ________ is a graph of cumulative distribution.

Ogive plot
question

Using the following data, describe the shape of the data distribution

skewed to rightt
question

Using the following data, what would be the range of the values of the stem in a stem and leaf display?

11-18
question

Using the following data, what would be the leaf unit in a stem and leaf display?

10
question

Consider the following data on distances traveled by people to visit the local amusement park and calculate the relative frequency for the shortest distance.

.375
question

Consider the following data on distances traveled by people to visit the local amusement park and calculate the relative frequency for the distances over 24 miles

.150
question

The following is a partial relative frequency distribution of grades in an introductory statistics course. Find the relative frequency for B grade

.37
question

The following is a relative frequency distribution of grades in an introductory statistics course. If this was the distribution of 200 students, find the frequency for the highest two grades:

118
question

The following is a relative frequency distribution of grades in an introductory statistics course. If this was the distribution of 200 students, find the frequency of failures

12
question

The following is a relative frequency distribution of grades in an introductory statistics course. If we wish to depict these data using a pie chart, find how many degrees should be assigned to the highest grade of A.

79.2
question

Recently an advertising company called 200 people and asked to identify the company that was in an ad running nationwide. The following results were obtained: What percentage of those surveyed were female and could not recall the company?

22.0%
question

Recently an advertising company called 200 people and asked to identify the company that was in an ad running nationwide. The following results were obtained: What percentage of those surveyed could not correctly recall the company?

58.00%
question

The local electronics retailer has recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. The following results were obtained: What percentage of purchases were Plasma televisions by customers with the smallest credit balances?

19.6%
question

The local electronics retailer has recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. The following results were obtained: What percentage of the customers with the highest credit balances purchased an LCD television?

5.9%
question

The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below: 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 How many classes should be used in the construction of a histogram?

5
question

The number of weekly sales calls by a sample of 25 pharmaceutical salespersons is below: 24, 56, 43, 35, 37, 27, 29, 44, 34, 28, 33, 28, 46, 31, 38, 41, 48, 38, 27, 29, 37, 33, 31, 40, 50 What is the shape of the distribution of the data?