# Overview

A car manufacturing company releases a new car and it claims that the car has a mileage of 20 kms per liter. Should we believe it or not? And why should or shouldn't we believe it? Hypothesis testing is a method that can be used to make decisions in such situations.

Hypothesis testing generally involves four steps.

- First, we develop two claims:
**null hypothesis** (*H*_{0}) and **alternative hypothesis** (*H*_{a}). In our case ‘the car can run 20 kms per liter’ is a null hypothesis and ‘the car can’t run 20 kms per liter’ is an alternative hypothesis. - Second, we
**collect a sample** (sample of newly manufactures cars) and collect relevant data from them and summarize it using statistics. - Then, we
**calculate** how probable it is to find the result from our analysis if the hypothesis was true. - Finally, we
**reach a conclusion** based on ou...