Questions and Answers
A frequency distribution groups data into classes showing the number of observations in each class.
True
A frequency distribution for qualitative data has class limits.
False
To summarize the gender of students attending a college, the number of classes in a frequency distribution depends on the number of students.
False
In frequency distributions, classes are mutually exclusive if each individual, object, or measurement is included in only one category.
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In a bar chart, the x-axis is labeled with the values of a qualitative variable.
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In a bar chart, the heights of the bars represent the frequencies in each class.
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The midpoint of a class, which is also called a class mark, is halfway between the lower and upper limits.
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A class interval, or class width, can be determined by subtracting the lower limit of a class from the lower limit of the next higher class.
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To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the sum of the class frequencies.
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To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the number of classes.
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A pie chart is similar to a relative frequency distribution.
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A pie chart shows the relative frequency in each class.
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To construct a pie chart, relative class frequencies are used to graph the 'slices' of the pie.
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A cumulative frequency distribution is used when we want to determine how many observations lie above or below certain values.
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A frequency polygon is a very useful graphic technique when comparing two or more distributions.
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Monthly commissions of first-year insurance brokers are $1,270, $1,310, $1,680, $1,380, $1,410, $1,570, $1,180, and $1,420. These figures are referred to as a(n) __________.
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A small sample of computer operators shows monthly incomes of $1,950, $1,775, $2,060, $1,840, $1,795, $1,890, $1,925, and $1,810. What are these ungrouped numbers called?
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When data is collected using a quantitative, ratio variable, what is true about a frequency distribution that summarizes the data?
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When data is collected using a qualitative, nominal variable, what is true about a frequency distribution that summarizes the data?
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When data is collected using a qualitative, nominal variable (in other words, male or female), what is true about a frequency distribution that summarizes the data?
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A student was interested in the cigarette smoking habits of college students and collected data from an unbiased random sample of students. The data is summarized in the following table.
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A student was interested in the cigarette smoking habits of college students and collected data from an unbiased random sample of students. The data is summarized in the following table:
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A student was interested in the cigarette smoking habits of college students and collected data from an unbiased random sample of students. The data is summarized in the following table:
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When a class interval is expressed as 100 up to 200, _________________________.
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For a relative frequency distribution, relative frequency is computed as _____________.
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The relative frequency for a class represents the ________________.
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A group of 100 students was surveyed about their interest in a new International Studies program. Interest was measured in terms of high, medium, or low. In the study, 30 students responded high interest, 40 students responded medium interest.
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Study Notes
Frequency Distribution
- A frequency distribution organizes data into classes, showing the number of observations per class.
- Frequency distributions for qualitative data do not have class limits.
- Classes in a frequency distribution must be mutually exclusive, meaning each observation belongs to one category only.
Bar Charts
- The x-axis of a bar chart is labeled with qualitative variable values.
- Bar heights represent frequencies for each class in a bar chart.
Class Characteristics
- The midpoint (class mark) of a class is located halfway between its lower and upper limits.
- Class intervals or widths can be calculated by subtracting the lower limit of a class from the lower limit of the next higher class.
Relative Frequency Distribution
- To create a relative frequency distribution, divide each class frequency by the total frequency, not the number of classes.
- Relative frequencies can be represented in a pie chart, showing proportional slices based on class frequencies.
Cumulative Frequencies
- A cumulative frequency distribution helps determine how many observations fall above or below specific values.
Visual Techniques
- A frequency polygon is useful for comparing multiple distributions visually.
Raw Data
- Monthly commissions or incomes provide examples of raw data, which is ungrouped and unprocessed numerical data.
Data Types and Frequency Distribution
- Quantitative ratio variables require calculation of upper and lower class limits in a frequency distribution.
- Qualitative nominal variables can be summarized using pie charts, with the number of classes corresponding to variable values.
Data Insights
- Observations such as income or smoking habits can be summarized in visual formats like bar charts or pie charts based on collected data.
- If a class interval is defined as 100 up to 200, it excludes observations equal to 200.
Relative Frequency
- Relative frequency is expressed as the class frequency divided by total frequency, indicating the percentage of total observations for that class.
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Description
Test your knowledge of frequency distributions and qualitative data in this quiz based on Statistics Chapter 2. Each card presents a statement that you need to evaluate as true or false. Join now to strengthen your understanding of statistical concepts!
