Book Image

Essential Statistics for Non-STEM Data Analysts

By : Rongpeng Li
Book Image

Essential Statistics for Non-STEM Data Analysts

By: Rongpeng Li

Overview of this book

Statistics remain the backbone of modern analysis tasks, helping you to interpret the results produced by data science pipelines. This book is a detailed guide covering the math and various statistical methods required for undertaking data science tasks. The book starts by showing you how to preprocess data and inspect distributions and correlations from a statistical perspective. You’ll then get to grips with the fundamentals of statistical analysis and apply its concepts to real-world datasets. As you advance, you’ll find out how statistical concepts emerge from different stages of data science pipelines, understand the summary of datasets in the language of statistics, and use it to build a solid foundation for robust data products such as explanatory models and predictive models. Once you’ve uncovered the working mechanism of data science algorithms, you’ll cover essential concepts for efficient data collection, cleaning, mining, visualization, and analysis. Finally, you’ll implement statistical methods in key machine learning tasks such as classification, regression, tree-based methods, and ensemble learning. By the end of this Essential Statistics for Non-STEM Data Analysts book, you’ll have learned how to build and present a self-contained, statistics-backed data product to meet your business goals.
Table of Contents (19 chapters)
1
Section 1: Getting Started with Statistics for Data Science
5
Section 2: Essentials of Statistical Analysis
10
Section 3: Statistics for Machine Learning
15
Section 4: Appendix

Learning about joint and conditional distribution

We have covered basic examples from discrete probability distributions and continuous probability distributions. Note that all of them describe the distribution of a single experiment outcome. How about the probability of the simultaneous occurrence of two events/outcomes? The proper mathematical language is joint distribution.

Suppose random variables X and Y denote the height and weight of a person. The following probability records the probability that X = x and Y = y simultaneously, which is called a joint distribution. A joint distribution is usually represented as shown in the following equation:

For a population, we may have P(X = 170cm, Y = 75kg) = 0.25. You may ask the question: What is the probability of a person being 170 cm while weighing 75 kg? So, you see that there is a condition that we already know this person weighs 75 kg. The expression for a conditional distribution is a ratio as follows...