(Intermediate Level)
1. Exploratory Data Analysis (EDA)
Descriptive Statistics: Mean, Median, Mode, Standard Deviation,
Variance
Data Visualization: Histograms, Boxplots, Scatter Plots, Pair
Plots
Correlation & Covariance: Pearson and Spearman correlation
Outlier Detection: Z-score, IQR method, Visual inspection
2. Data Wrangling & Cleaning
Handling Missing Data: Imputation techniques (mean, median,
mode, KNN, regression)
Data Transformation: Encoding categorical variables (One-Hot,
Label Encoding)
Feature Engineering: Creating new features, Feature scaling
(Normalization, Standardization)
Dealing with Duplicates & Anomalies
3. SQL for Data Analysis
Basic Queries: SELECT, WHERE, GROUP BY, ORDER BY,
HAVING
Joins & Subqueries: INNER, LEFT, RIGHT, FULL JOINs,
Common Table Expressions (CTEs)
Aggregation Functions: COUNT, SUM, AVG, MIN, MAX
Window Functions: ROW_NUMBER(), RANK(), LEAD(),
LAG()