How To Know Which Statistical Test To Use For Hypothesis Testing

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My name is Kody Amour, and I provide online math lectures to the public. My aim is to provide content that attends to a sound, productive conceptual understanding. Basically, I want to make sense, and I want my videos to be coherent with each other. If you think that these videos have helped you, please consider supporting this channel by subscribing, and please consider donating to this cause via Patreon!

[quantquill]

We do not use a t-test for a one-sample test for proportion. We use the z distribution. I teach undergraduate and graduate statistics and have reviewed a dozen statistics textbooks and with 99% confidence, claim that we do not use the Student's t-distribution when testing a proportion. From the Stats Stackexchange: "The reason you can use a z-test with proportion data is because the standard deviation of a proportion is a function of the proportion itself. Thus, once you have estimated the proportion in your sample, you don't have an extra source of uncertainty that you have to take into account." Z distribution doesn't ask for sample size to determine the critical value, whereas t distribution does. However, as sample size gets large, z and t converge until t = z. For example, the sample size of 1000 would have no difference between z and t values.

[aflowerthatbloomsinadversity]

Spent 16 weeks in a graduate level stats class, but learned everything I needed to know in this 20 minute video. Thanks! Super clear.

[Misterzr]

There is nothing wrong with the 1-sample z test. It produces the correct answers as long as you have the population parameters. But because we rarely have the population parameters we don't use it. Its not inherently flawed as implied by the host of the video. It's pretty easy to explain why it isn't used very often, like I just did. Otherwise, great video.

[siddharthvm]

Great video!

Just wanted to share my 2 cents.

We don't use z tests because they require for us to have the population statistics (population mean and standard deviation) to do our analysis whereas in a T-test we just require the sample statistics (sample mean and standard deviation) to go ahead.

Since in many cases we are just comparing 2 samples and we might not have the population statistics (especially standard deviation), we use T-tests instead of the z tests.

Hope this helps!

[aishwaryar]

The fact he explained the entire semester statistics portion in 20 minutes clear and precise. Amazing 🔥

[LengForChrist]

I am from the university of Jos, Plateau State, Nigeria and l have never learned well during the masters degree statistics classes l took for one year+ but you make it look simple. You are a good communicator and l feel more confident about my statistics knowledge because of you.

[filipinaandtheworld]

I’m on a PhD level program with a statistics course and this is incredibly useful sir. You deserve 22 million subscribers!

[KatoOnTheTrack]

I’m a mechanical engineer. Of course we took the appropriate statistics and probability class but never saw the real significance until my 5th year of being an engineer and working at GE healthcare. Now I apply the DMAIC approach as much as needed.

[jamiyana]

Simply the greatest explanation. I spent hours trying to get the main gist and difference of all these confusing test. This video was the brilliant saver for me. Thank you so much

[jennifervazquez]

saved me so much time researching the appropriate technique I should use to test my hypothesis. Glad i watched it

[jermelpurse]

I’m not statistician but I’ve been in the statistics classes at least all three or four you might take during your undergraduate year and when you learn about those particular test they also tell you when you should use them. That’s part of learning about the actual test. I think that’s where we’re having a breakdown in the education process now statistics is more college level but even on a more basic level we might learn how to do math but we don’t learn the principles behind the mathematics you should learn the principles behind the statistics tests then you know when to use them

[girlwithquestions]

This was super helpful in so many levels. Not only did you described the tests in detail without hassle but it helped me understand when to use them. Thanks!!

[BillyMathews]

Dude I spent $70, 000 on a PhD in Boston and could have saved every penny had I seen this before. Thanks your fantastic.

[dr]

Theres no such thing as t-test for proportion.
As tests involving single and two proportions, which are technically binomial, may only be estimated by a normal distribution (hence, z test), and not by t-distribution.

[hiyaguha]

Kody, Thank you so much. I have spent days trying to figure out ANOVA versus Chi Square versus T tests and so on, and you made it so easy. I am really grateful --and also a little baffled that so many other sources make it so complex.

[eagelnest]

For whatever distribution shape of population, you take a sample of size >25, the average value (mean) itself is normal distribution, and you use Z-test. For a smaller sample size, we need to consider degree of freedom, then you use t-test.

[TheColorField]

You use the Z-test when you know something about the population standard deviation. This doesn't happen very often, so the t-test is more common. Saying you should never use it, or that it's "bad" or "dumb" or "unprofessional" is just NOT accurate. It's just more RARELY used. Throwing it out shows a lack of understanding.

[ladydove]

Where have you been all my statistics life? WOW!! Just brilliant...thank you so much.

[uncutit]

Woow woow this is the most clear version of understanding which test, when, where and how to use the statistical test. Thank you

[JamesPavlaine]

there is no equivalent t-test for one sample proportion due to the binomial approximation in these cases so only z -test for one proportion samples