2: Displaying And Describing Categorical Data Flashcards
1
Q
What is the first rule of data analysis?
A
Make a picture.
2
Q
What does making a picture of data help to reveal?
A
Patterns and relationships that may be hiding in your data.
3
Q
Why is a well-designed display important in data analysis?
A
It shows the important features and patterns in your data.
4
Q
What can a picture of data show besides expected features?
A
Extraordinary (possibly wrong) data values or unexpected patterns.
5
Q
How can you effectively tell others about your data?
A
With a well-chosen picture.
6
Q
What is a frequency table used for?
A
To organize and summarize data more effectively.
7
Q
Fill in the blank: The best way to _____ others about your data is with a well-chosen picture.
A
[tell]
8
Q
True or False: Technology makes it difficult to draw pictures of data.
A
False.
9
Q
What is a frequency table?
A
A table that counts the number of cases corresponding to each category.
10
Q
What categories are used for ticket class in the Titanic data?
A
- First
- Second
- Third
- Crew
11
Q
When dealing with a variable with many categories, what is a useful strategy?
A
Combine categories into larger headings.
12
Q
How can states be grouped when counting students attending a university?
A
- Northeast
- South
- Midwest
- Mountain States
- West
- Other
13
Q
What is a relative frequency table?
A
A table that displays the proportions or percentages of values in each category.
14
Q
What does the area principle state?
A
The area occupied by a part of the graph should correspond to the magnitude of the value it represents.
15
Q
What issue arises from violating the area principle in data displays?
A
It can distort the understanding of the data.
16
Q
What is a bar chart?
A
A chart that uses bars to represent the counts for each category.
17
Q
In a bar chart, what determines the area of each bar?
A
The height of each bar.
18
Q
How does a bar chart help in data comparison?
A
It makes comparisons easy and natural.
19
Q
What visual impression can misleading data displays create?
A
They can create an inaccurate impression of the distribution of data.
20
Q
True or False: The area of a graph should not correspond to the value it represents.
A
False.
21
Q
Fill in the blank: A relative frequency table shows __________ or percentages instead of counts.
A
[proportions]
22
Q
Why is it important to follow the area principle in data representation?
A
To ensure that the visual representation accurately reflects the data.
23
Q
What common mistake can occur when designing graphs?
A
Creating a graph that violates the area principle.
24
Q
How can the distribution of a categorical variable be described?
A
By naming the possible categories and telling how frequently each occurs.
25
What do bar charts display?
The distribution of a categorical variable, showing the counts for each category.
26
What is the difference between a relative frequency bar chart and a regular bar chart?
A relative frequency bar chart shows the proportion of people in each category rather than the counts.
27
Which axis in a relative frequency bar chart may read 0, 0.10, 0.20, 0.30, 0.40?
The vertical axis.
28
What should be included between bars in a bar chart?
Spaces to indicate that the bars are freestanding.
29
What is a pie chart used for?
To show how a whole group breaks into several categories.
30
What does a pie chart represent?
The whole group of cases as a circle, sliced into pieces proportional to the fraction of the whole in each category.
31
What is a good scenario for using a pie chart?
When visualizing relative frequencies near 1/2, 1/4, or 1/8.
32
What is the first rule of data analysis?
Make a picture.
33
What is crucial to check before making a bar chart or pie chart?
The Categorical Data Condition that the data are counts or percentages of individuals in categories.
34
True or False: Categories in a pie chart can overlap.
False.
35
Fill in the blank: A bar chart may be used to display the _______ of a categorical variable.
[distribution]
36
How many passengers were in First Class on the Titanic?
325.
37
How many passengers were in Third Class on the Titanic?
706.
38
How many passengers were in Second Class on the Titanic?
285.
39
What is an important consideration when creating a relative frequency bar chart?
Ensure that the categories do not overlap.
40
What type of chart is better for comparing quantities, bar charts or pie charts?
Bar charts.
41
What do bar charts display?
The distribution of a categorical variable, showing the counts for each category.
42
What is the difference between a relative frequency bar chart and a regular bar chart?
A relative frequency bar chart shows the proportion of people in each category rather than the counts.
43
Which axis in a relative frequency bar chart may read 0, 0.10, 0.20, 0.30, 0.40?
The vertical axis.
44
What should be included between bars in a bar chart?
Spaces to indicate that the bars are freestanding.
45
What is a pie chart used for?
To show how a whole group breaks into several categories.
46
What does a pie chart represent?
The whole group of cases as a circle, sliced into pieces proportional to the fraction of the whole in each category.
47
What is a good scenario for using a pie chart?
When visualizing relative frequencies near 1/2, 1/4, or 1/8.
48
What is the first rule of data analysis?
Make a picture.
49
What is crucial to check before making a bar chart or pie chart?
The Categorical Data Condition that the data are counts or percentages of individuals in categories.
50
True or False: Categories in a pie chart can overlap.
False.
51
Fill in the blank: A bar chart may be used to display the _______ of a categorical variable.
[distribution]
52
How many passengers were in First Class on the Titanic?
325.
53
How many passengers were in Third Class on the Titanic?
706.
54
How many passengers were in Second Class on the Titanic?
285.
55
What is an important consideration when creating a relative frequency bar chart?
Ensure that the categories do not overlap.
56
What type of chart is better for comparing quantities, bar charts or pie charts?
Bar charts.
57
What are the three choices for the percentage in a contingency table?
By row, by column, and by table total
## Footnote
These options help in understanding the distribution of data across different categories.
58
What is the joint distribution of two variables?
The percentages that tell us what percent of all passengers belong to each combination of column and row category
## Footnote
This concept is crucial for understanding relationships between categorical variables.
59
What percent of the people aboard the Titanic were surviving third-class ticket holders?
8.1%
## Footnote
This statistic indicates the proportion of third-class passengers who survived.
60
What percent of the people aboard the Titanic were surviving second-class ticket holders?
5.4%
## Footnote
This statistic indicates the proportion of second-class passengers who survived.
61
What does comparing overall percentages not answer?
Whether second-class passengers were more or less likely to survive than third-class passengers
## Footnote
Overall percentages can be misleading without considering the sample size of each category.
62
What is the denominator when asked, 'What percent of the survivors were in second class?'
Only the survivors
## Footnote
This focuses the analysis on the subgroup of interest.
63
What is the denominator when asked, 'What percent were second-class passengers who survived?'
2201
## Footnote
This includes all passengers on board, providing a different perspective on survival rates.
64
What is the denominator when asked, 'What percent of the second-class passengers survived?'
285
## Footnote
This focuses on the second-class passengers specifically.
65
Why is it important to ask 'percent of what?'
To know who we're talking about and whether to use row, column, or overall percentages
## Footnote
This question clarifies the context and ensures accurate interpretation of data.
66
What issue arises when statistics programs combine multiple percentage types in each cell of a table?
The resulting table holds lots of information but can be hard to understand
## Footnote
Clarity is crucial for effective data analysis.
67
What is the overall percent for the total in the example provided?
100%
## Footnote
This indicates that all categories of data are accounted for.
68
What is the overall percentage of survival for the crew as mentioned in the data?
40.2%
## Footnote
This figure reflects the survival rate among crew members.
69
What does conditional distribution analyze in the context of survival?
The chance of survival depending on ticket class.
70
How can the distribution of ticket class be examined between survivors and nonsurvivors?
By looking at the row percentages.
71
What percentage of first-class passengers survived?
28.6%
72
What percentage of second-class passengers survived?
16.6%
73
What percentage of third-class passengers survived?
25.0%
74
What percentage of crew members survived?
29.8%
75
What is the total number of passengers who died?
711
76
What is the total number of passengers on board?
1490
77
Fill in the blank: The survival rate for first-class passengers was _______.
28.6%
78
True or False: More third-class passengers survived than second-class passengers.
True
79
List the survival percentages for each ticket class.
* First Class: 28.6%
* Second Class: 16.6%
* Third Class: 25.0%
* Crew: 29.8%
80
What is the total number of survivors?
779
81
Fill in the blank: The percentage of second-class passengers who died was _______.
11.2%
82
What does each column in a contingency table represent?
The conditional distribution of survival for a given category of ticket class.
83
What are conditional distributions?
Distributions that show the distribution of one variable for cases that satisfy a condition on another variable.
84
What is the sum of percentages in each row of a contingency table?
100%.
85
How are pie charts used in the context of a contingency table?
To show the distribution of ticket classes for survivors and nonsurvivors.
86
What percentage of women look forward to seeing Super Bowl commercials more than the game itself?
30%.
87
What percentage of men look forward to seeing Super Bowl commercials more than the game itself?
17%.
88
How do you find the distribution of survival for each category of ticket class?
Look at the column percentages.
89
What does the column percentages in a contingency table add up to?
100%.
90
What information does the table provide about ticket class in relation to survival?
Ticket class made a difference in terms of whether a passenger survived.
91
Fill in the blank: The table shows results of a poll asking adults whether they were looking forward to the Super Bowl game, looking forward to the ________, or didn't plan to watch.
commercials.
92
True or False: The percentages of survival and nonsurvival can be displayed in a side-by-side bar chart for each ticket class.
True.
93
What were the total counts for survivors and nonsurvivors in the provided data?
Total survivors: 711, Total nonsurvivors: 1490.
94
What percentage of the second class survived according to the table?
41.4%.
95
What is the total count of passengers in the provided data?
2201.
96
What is the distribution of survival for the third class?
25.2%.
97
What type of charts are used to show the conditional distribution of Survival for each category of ticket Class?
Side-by-side bar charts
## Footnote
Bar charts are preferred over pie charts when comparing multiple categories.
98
What percentage of first-class passengers perished in the Titanic disaster?
37.5%
## Footnote
This statistic highlights the survival rate among different ticket classes.
99
What percentage of second-class passengers perished in the Titanic disaster?
58.6%
## Footnote
This statistic is part of the comparative analysis of survival rates.
100
What percentage of third-class passengers perished in the Titanic disaster?
74.8%
## Footnote
This statistic indicates the higher risk faced by third-class passengers.
101
What percentage of crewmembers perished in the Titanic disaster?
76.0%
## Footnote
This statistic suggests that crewmembers had a high fatality rate.
102
What does it indicate if survival rates are similar across different ticket classes?
Survival was independent of class
## Footnote
Independent survival rates would suggest no association between class and survival.
103
What is a contingency table used for?
To explore the dependence between two variables
## Footnote
It helps in analyzing the relationship between categorical variables.
104
How do we determine if two variables are independent?
If the distribution of one variable is the same for all categories of another
## Footnote
This indicates no association between the variables.
105
What reasoning method is commonly used in science and statistics to assess variable relationships?
Backward reasoning
## Footnote
This method involves deducing relationships based on observed data.
106
Fill in the blank: When only two categories exist for a variable, knowing the percentage of one category tells us the percentage of the _______.
other category
## Footnote
This is due to the complementary nature of the categories.
107
What does the presence of significant differences in conditional distributions suggest?
Survival may have depended on ticket class
## Footnote
Variability in survival rates indicates a potential association.
108
What type of chart is used to display survival rates in the provided data?
Segmented bar chart
## Footnote
A segmented bar chart treats each bar as the 'whole' and divides it proportionally into segments.
109
In what way does a segmented bar chart differ from a pie chart?
A segmented bar chart divides bars proportionally, while a pie chart represents parts of a whole as slices of a circle.
## Footnote
The segmented bar chart allows for clearer comparisons between groups.
110
What is the purpose of converting numbers to percentages in the provided data?
To allow for comparison of different groups on the same scale
## Footnote
This helps visualize the relative proportions of survivors and nonsurvivors.
111
What does the height of the bars represent in a segmented bar chart?
The total for survivors and nonsurvivors
## Footnote
Bars are the same height when comparing totals across different groups.
112
True or False: The segments in a segmented bar chart correspond to the percentage in each group.
True
## Footnote
Each segment visually represents the proportion of that group within the total.
113
Fill in the blank: A segmented bar chart treats each bar as the _______.
[whole]
## Footnote
This allows for proportional division into segments.
114
What type of study is mentioned in relation to fatty acid consumption and prostate cancer risk?
Observational study
## Footnote
Observational studies often analyze data without manipulating variables.
115
What specific population was analyzed in the study?
6272 Swedish men
## Footnote
The study aimed to learn about the dietary habits of this specific group.
116
What dietary habit was being investigated for its association with prostate cancer?
Fish consumption
## Footnote
The study raised questions about whether eating fish was linked to lower cancer rates.
117
What was one conclusion drawn from the study regarding fatty acids?
They may increase the risk of prostate cancer
## Footnote
This conclusion is based on data collected from a cancer prevention trial.
118
During what years was the cancer prevention trial conducted that involved 3400 men?
1994 to 2003
## Footnote
This trial collected data to analyze the relationship between diet and prostate cancer.
119
True or False: Observational studies can control all other factors affecting the study outcomes.
False
## Footnote
Observational studies cannot control all variables, which can lead to contradictory results.
120
Fill in the blank: The study aims to learn about the experiences of _______.
a larger population
## Footnote
Understanding a sample can provide insights applicable to broader demographics.
121
What is a potential issue with observational studies mentioned in the text?
They often lead to contradictory results
## Footnote
This is due to the inability to control for all influencing factors.
122
What alternative explanation is suggested regarding the dietary habits of men who eat fish?
Other habits may distinguish them from others
## Footnote
These habits, rather than fish consumption alone, might contribute to lower cancer rates.
