Questions and Answers
What does the statement 'typically, men in a certain country still earn more than women' mean?
The center of the distribution of salaries for men in the country is greater than the center for women.
What does the claim that houses with swimming pools tend to sell for less than those without mean?
The typical price for homes with pools is smaller than the typical price for homes without pools.
Would the standard deviation of the running times for the 100-meter race be larger or smaller than that of the men's marathon?
Smaller.
Which team would you think has a larger standard deviation of weights: a high school soccer team or a high school academic decathlon team?
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The _____ is another term for the arithmetic average.
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The mean of a collection of data is located at the ______ of a distribution of data.
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What does the symbol ∑ stand for?
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For what type of distribution does the mean represent the typical value?
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The _____ is a number that measures how far away the typical observation is from the mean.
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What should one do to compute the variance?
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Which is more unusual, an IQ of 90 or an IQ of 105, given a mean of 95 and a standard deviation of 5?
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In a roughly bell-shaped distribution of gestation periods, which is more unusual: a baby being born 10 days early or 10 days late?
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According to the Empirical Rule, ________ will be within two standard deviations of the mean.
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The Empirical Rule applies to distributions that are ________.
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What does a standard unit measure?
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What does a z-score of 0 indicate about an observation?
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Which can be used to compare values measured in different units?
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Name two measures of the variation of a distribution and their preferred conditions.
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The value that would be right in the middle if you were to sort the data from smallest to largest is called the ______.
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For what purpose is the median used?
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The median is often used for which types of distribution?
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The interquartile range tells us how much space the _____ of the data occupy.
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How can you recognize when an observation is an outlier?
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Study Notes
Salary Distribution
- Men's salaries are typically higher than women's in certain countries, indicating a disparity in salary distribution.
Real Estate Pricing
- Houses with swimming pools generally sell for lower prices compared to those without, assuming other conditions are equal.
Standard Deviation in Competitions
- Running times for the 100-meter race have a smaller standard deviation compared to marathon times due to closer finish times among sprinters.
Weight Distribution in Teams
- The academic decathlon team likely has a larger standard deviation of weights, reflecting a diverse distribution similar to the general population, unlike performance-focused teams.
Mean
- The arithmetic average of a data set is known as the mean.
Balancing Point
- The mean acts as the "balancing point" in a distribution of data.
Summation Symbol
- The symbol ∑ represents the summation of data points.
Distribution Symmetry
- The mean is representative of the typical value in symmetric distributions.
Standard Deviation Definition
- Standard deviation quantifies how much individual observations deviate from the mean.
Variance Calculation
- To obtain variance, one must square the standard deviation.
IQ Test Scores and Unusualness
- An IQ of 105 is considered more unusual than 90, as it has a higher z-score, indicating a greater distance from the mean.
Gestation Periods
- A baby being born 10 days early and a baby being born 10 days late are equally likely occurrences in gestation periods.
Empirical Rule
- Approximately 95% of observations lie within two standard deviations of the mean according to the Empirical Rule.
Conditions for the Empirical Rule
- The Empirical Rule is applicable to symmetric and unimodal distributions.
Standard Units Measurement
- Standard units indicate how many standard deviations an observation is from the mean.
Z-Score Interpretation
- A z-score of 0 signifies that an observation is exactly equal to the mean.
Comparing Different Units
- Z-scores allow for the comparison of values measured in different units (e.g., inches vs. pounds).
Variation Measures
- The interquartile range is more appropriate for skewed data or data with outliers; standard deviation is preferred for symmetric data.
Median Definition
- The median is the central value when data is arranged in order from smallest to largest.
Purpose of the Median
- The median provides a typical value representing a data set.
Median in Distributions
- Medians are commonly utilized in skewed distributions to represent central tendency.
Interquartile Range
- The interquartile range indicates the span of the middle 50% of the dataset.
Outlier Recognition
- Outliers can be identified as values that significantly deviate from the rest of the data set, often varying notably from the mean and median.
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Description
This set of flashcards covers key concepts from Statistics Chapter 3, focusing on salary distribution and market trends. Understand the implications of sociological and economic statements regarding men's and women's earnings, as well as property values in real estate. Perfect for students looking to reinforce their understanding of these critical statistical ideas.
