You might be thinking who starts day 1 with Statistics but I want to tell you that I have a BSc Computer Science background. so I am familiar with Python and a few of the modules and I am very confident in my Python skills and that's why I'm starting my journey with statistics.
Introduction to Statistics
Def: Statistics is the discipline that concerns the collection, organization, analysis, interpretation and presentation of data - Krish Naik
Yes you read that right I started learning stats from Krish Naik's YouTube channel and he's good with this stuff
Statistics comes in 2 types which are Descriptive Statistics and Inferential Statistics, Going further we will see what is the difference between these 2 types of statistics.
Descriptive Statistics
Descriptive Statistics consists of Analyzing the data, Summarizing the data and to be more precise it consists Organizing the data in the form of Numbers and Graphs
It consists of a Bar Plot, histogram, Pie Chart, PDF (Probability Density Function), CDF (Cumulative Density function), Normal Distribution or Gaussian Distribution.
we can also say that the Measure of Central Tendency i.e Mean, Median and Mode also comes under Descriptive Statistics
Descriptive Statistics also have Measures of Variance i.e. Standard Deviation and variance.
Inferential Statistics
In Inferential Statistics we take a sample from a population and perform some tests on the population and then we come up with some inference and solution for that specific population data.
ah! Don't worry I'll not just mug you up with this definition kind of thing but I'll also give you an example of Inferential Statistics and you'll understand what the above paragraph means.
Eg: suppose there is a cricket competition going on in a school and 4 teams participating in that competition from Classes A, B, C & D from the entire school we have to find the exit poll which means we want to know which team has more chance of winning.
In this scenario, the entire school is our Population Datad and classes A, B, C & D are our sample data.
Now to find the exit poll we go to this sample data which is classes A, B, C & D and we ask people of these classes about their opinions of which of the teams is going to win and then we calculate the percentage based on the opinion of this subsets
In the end, we can say which of the teams has more number of percentage wins.
With this example, we can say that Inferential Statistics is all about performing different tests on the dataset.
Inferential Statistics consists of tests like Z - Test, T-Test, Chi-square Test etc.
This was all about the Introduction of Statistics and the difference between Descriptive and Inferential Statistics.