Machine Learning - Steps in Hypothesis Testing - Traditional Method

In this video we are going to discuss steps in hypothetical testing a traditional method

A statistical hypothesis is a conjecture about a population parameter and this conjecture may or may not be true

So here we are forming one conjecture on the population parameter. There are two types of statistical hypothesis for each situation

The first one is the null hypothesis. one is the null hypothesis and another one is the alternative hypothesis

So, let us discuss with them some detailing. So the null hypothesis symbolized by h0

So this null hypothesis will be symbolized by h0 and is a statistical hypothesis that

states that there is no difference between a parameter and a specific value, or that there

is no difference between two parameters. So, that is the basic theme behind this null hypothesis

The alternative hypothesis symbolized by H1 is a statistical hypothesis that states that existence

of a difference between a parameter and a specific value. Or states that there is a difference between two parameters So here we are observing that there is no difference between two parameters or there is a particular parameter and a specific value there will be no difference

but here in case of alternative hypothesis where we are just demanding that, yes, there is one

difference between the two parameters or a parameter and a specific value

So, let us go for one example at first. So, a chemist invents an additive to increase the life of an automobile battery

So, chemist has invented an additive to increase the life of an automobile battery

If the mean lifetime of the automobile battery without the additive is 36 months, then her

hypothesis are, these are null hypothesis which will be expressed in the form of 80, is mu is equal

to 36 and H1 that is mu is greater than 36. So without the additive, if the average lifetime is about 36 months, then in that case

in case of alternative hypothesis, this particular mu that is the average age of the battery

lifetime will be greater than 36 because this particular additive has been invented to increase the lifetime of the battery So in this situation the chemist is interested only in increasing the lifetime of the batteries So her alternative hypothesis is that the mean is greater than 36 months

The null hypothesis is that the mean is equal to 36 months

So this test is called right-tailed test, because the interest is in an increase. only

So, let us go for another example. That is example number two

A contractor wishes to lower heating bills by using a special type of insulation in houses

If the average of the monthly heating bills is $78, her hypothesis about heating cost

with the use of insulation are, so 8-0, null hypothesis is equal to, mu is equal to

to $78 and H1 that is the alternative hypothesis will be mu is less than $78

This test is called left-tailed test since the contractor is interested only in lowering the

heating costs. This is our example number 3. Will the pulse rate increase decrease or remain unchanged after a patient takes a particular medication So that is the problem we are having Since the researcher knows that the mean pulse rate of for the population under study is 82 bits per minute

the hypothesis for this situations are for the null hypothesis, the mu will be equal to 82

and for alternative hypothesis H1, mu will be not equal to 82

And this test is called two-tailed test. So, let us go for a summary of all these different types of hypotheses

Here, the null and alternative hypotheses are stated together. And the null hypothesis contains the equal to sign as shown here

So now here, K represents a specified number. So, in case of two-tail test, the null hypothesis will be mu is equal to k, and

And in case of alternative, it will be mu is not equal to k

This null hypothesis for right tail test will be 8-0, that is our mu is equal to k, and

H-1 mu is greater than k. And in the left-tail test, the H-0 will be mu is equal to k, and H-1 will be mu is less

than k. So in this way, we have discussed what is null hypothesis and what is ordinative hypothesis

with some examples. Thanks for watching this video