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Descriptive statistics
P R AC TIC IN G STATISTIC S IN TE R VIE W QU E STION S IN P YTH ON
Conor Dewey
Data Scientist, Squarespace
PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
What are descriptive statistics?
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Descripti v e statistics P R AC TIC IN G STATISTIC S IN TE R VIE W - - PowerPoint PPT Presentation
Descripti v e statistics P R AC TIC IN G STATISTIC S IN TE R VIE W - - PowerPoint PPT Presentation
Descripti v e statistics P R AC TIC IN G STATISTIC S IN TE R VIE W QU E STION S IN P YTH ON Conor De w e y Data Scientist , Sq u arespace What are descripti v e statistics ? 1 Wikimedia PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON Meas
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Measures of centrality
Mean Median Mode
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Measures of centrality
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
σ = 0.25 σ = 1 mode median mean
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Measures of variability
Variance Standard deviation Range
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Measures of variability
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Modality
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Skewness
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Summary
Dening descriptive statistics Mean, median, and mode Standard deviation and variance Modality and skewness
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Let's prepare for the interview!
P R AC TIC IN G STATISTIC S IN TE R VIE W QU E STION S IN P YTH ON
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Categorical data
P R AC TIC IN G STATISTIC S IN TE R VIE W QU E STION S IN P YTH ON
Conor Dewey
Data Scientist, Squarespace
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Types of variables
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Encoding categorical data
What is One Hot Encoding and How to Do It
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Example: laptop models
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Example: laptop models
company_count = df['Company'].value_counts() sns.barplot(company_count.index, company_count.values)
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Box plots
- utliers
lower whisker upper whisker upper quartile lower quartile median Wikimedia
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Example: laptop models
df.boxplot('Price', 'Company', rot = 30, figsize=(12,8), vert=False)
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Summary
Types of variables Encoding techniques Sample exploratory data analysis
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Let's prepare for the interview!
P R AC TIC IN G STATISTIC S IN TE R VIE W QU E STION S IN P YTH ON
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Two or more variables
P R AC TIC IN G STATISTIC S IN TE R VIE W QU E STION S IN P YTH ON
Conor Dewey
Data Scientist, Squarespace
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Types of relationships
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
What is correlation?
Statistical relationship between variables Stronger correlation = more information
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Covariance
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Pearson's correlation
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Pearson's correlation
1 0.8 0.4
- 0.4
- 0.8
- 1
1 1 1
- 1
- 1
- 1
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Correlation vs. causation
xkcd
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Correlation vs. causation
Correlation does not mean Causation
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PRACTICING STATISTICS INTERVIEW QUESTIONS IN PYTHON
Summary
Types of relationships Review of correlation Covariance Pearson's correlation Correlation vs. causation
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Let's prepare for the interview!
P R AC TIC IN G STATISTIC S IN TE R VIE W QU E STION S IN P YTH ON