What is Correlation? Correlation is a statistical measure of the relationship between two variables, X and Y. For instance, you can measure to what extent temperature (X) is related to the production of ice cream (Y). You probably would expect that higher temperatures correspond with higher production of ice cream. On the plot shown below, … Read more
How to Write Null and Alternative Hypotheses
Since both correlation and t-test are about relationships between X and Y, what is the difference between them and when do you use t-test (or correlation)? This tutorial aims to answer these two questions. The following figure presents the difference between t-test and correlation. In particular, t-test deals with situations where X is a binary … Read more
This tutorial explains what t-test is, and the difference between independent sample t-test and paired sample t-test. It also explains what two-sample and one-sample t-test are. What is independent sample t-test? Indepdent sample t-test examines whether the means from 2 separate groups of people or objects are statistically significantly different. That is, we calculate two … Read more
This tutorial explains the difference between scatter plots and line charts in data visualization. I will use actual data and Python code to illustrate the nuanced difference between them. Data is pulled from Github. It includes keywords of Peloton and Covid as the search queries in Google Trends from early 2020 to early 2022. For … Read more
This short tutorial shows how you can calculate standard deviation in Python using NumPy.