#### Hypothesis testing

It provides an approach to making inference about a population on the basis of sample information. Decisions are made under uncertainty. The idea behind hypothesis testing is to develop a statistical tool to minimize the probability of error.

The method consists of selecting a sample to check the validity of a conjecture or hypothesis.

##### Null and alternative

The maintained hypothesis or conjecture is called Ho. The alternative hypothesis (H1) is a conjecture assumed to be true if Ho is false.

##### Objective

The objective of the test is to show evidence against the null. The typical analogy is when evidence is presented against a defendant, the null is that the defendant is inocent.

It consists of selecting a sample to check the validity of a conjecture or hypothesis. It provides an approach to making inference about a population on the basis of sample information.

##### Elements of a test of hypothesis
1. Null Ho
2. Alternative H1
3. Test statistic
4. Rejection region (or level of significance)