• 0:00 - 0:04
So this is where we draw the line, any outcome over here is critical.
• 0:04 - 0:11
That means so any of those outcomes, you'll be so surprised that we reject the null hypothesis.
• 0:11 - 0:16
Whereas any outcome in the region over here is okay, so we accept it.
• 0:16 - 0:20
Notice subtlety here. Even outcome 11 is okay.
• 0:20 - 0:25
Despite the fact that 11 is very surprising, it comes to the probability less than 5%,
• 0:25 - 0:28
but that's not the way to look at this.
• 0:28 - 0:34
The more frequently your sample, the more unlikely each individual outcome is.
• 0:34 - 0:36
Look at the outcome as blocks.
• 0:36 - 0:41
When you implement hypothesis testing, there'll be something like a most likely outcome.
• 0:41 - 0:46
Somewhere between 13 and 14, I guess it's 14. That outcome has to be okay obviously.
• 0:46 - 0:53
If you see that, you'll be happy and then you push this in one direction towards H₁,
• 0:53 - 1:00
the alternate hypothesis until all the probabilities remaining
• 1:00 - 1:04
cover 5% or less and that's the critical region.
• 1:04 - 1:12
So let's give this another try. Last Saturday, I went to the magic store and bought a loaded coin.
• 1:12 - 1:18
I paid a lot of money for it and the wizard that sold me the coin told me
• 1:18 - 1:21
the probability of head is equals 0.3.
• 1:21 - 1:25
In fact, there are many buckets of coins, the fair ones
• 1:25 - 1:31
the slightly loaded, all the way to the fully loaded, and those guys are cheap and those guys are cheap
• 1:31 - 1:34
but this one over here was really expensive.
• 1:34 - 1:36
So I wanted to make sure that I really got a loaded coin.
• 1:36 - 1:42
Let's first ask, what's our null hypothesis. Here are our choices for the probability of heads.
• 1:42 -
Pick the one that's best describes the null hypothesis.
Title:
Description:

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Video Language:
English
Team:
Udacity
Project:
ST101 - Intro to Statistics
Duration:
01:47