Descriptive Statistics
- Mean
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The average value of a dataset.
- Median
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The middle value in a dataset when it’s sorted.
- Mode
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The most frequent value in a dataset.
- Range
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The difference between the largest and smallest values.
- Variance
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A measure of how spread out the data is.
- Standard Deviation
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The square root of the variance, also a measure of spread.
- Interquartile Range (IQR)
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The range between the first quartile (Q1) and the third quartile (Q3).
- Z-score
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A measure of how many standard deviations a data point is from the mean.
- Frequency Distribution
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A table or graph showing how often different values occur.
- Histogram
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A bar graph where the bars are touching.
Inferential Statistics
- Sampling
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Selecting a subset of a population to study.
- Probability
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The likelihood of an event occurring.
- Hypothesis Testing
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Testing a claim about a population parameter.
- Confidence Intervals
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A range of values that is likely to contain the population parameter.
- Correlation
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The relationship between two variables.
- Regression Analysis
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Predicting the value of one variable based on the value of another.
- ANOVA (Analysis of Variance)
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Comparing the means of multiple groups.
- Chi-Square Test
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Testing for independence between categorical variables.
Data Visualization
- Bar Charts
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Comparing categories.
- Line Charts
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Showing trends over time.
- Pie Charts
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Representing parts of a whole.
- Scatter Plots
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Showing the relationship between two variables.
- Box Plots
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Summarizing the distribution of data.
Key Terms and Concepts
- Population
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The entire group being studied.
- Sample
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A subset of the population.
- Parameter
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A numerical characteristic of a population.
- Statistic
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A numerical characteristic of a sample.
- Data
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A collection of observations.
- Variable
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A characteristic that can take on different values.
- Discrete Variable
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A variable that can take on only specific values.
- Continuous Variable
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A variable that can take on any value within a range.