Statistics 101: Single Sample Hypothesis Z-test Concepts 

Mr. Foltz, this labor of love that you have created is invaluable. I cannot thank you enough for all you are doing to present a very digestable and understandable modality for comprehension of very abstract and non-intuitive content. The field of statistics is so very valuable, yet what goes on under the hood has been reserved for a very select group of dedicated scholars. I cannot thank you enough for creating these video tutorials. You are a gifted educator and have left both a priceless contribution and a significant legacy of amazing instruction; broadening the field of accessibility for future students of statistics. THANK YOU!!!!!

You are doing an amazing job, Brandon!! Please never stop!! On-line learning with the right professors are the best!! ...especially for adults who more often than not, drag themselves to a university classroom to sit in a classroom for an hour, coming out a little more informed or confused than before he or she went in. You can pause the video at any moment to reflect on the information. You can replay the lecture over and over!! WAKE UP UNIVERSITIES AND STOP ROBBING THE STUDENTS!!!

Watching in 2022. Thanks Brandon. This video is a life saver and a game changer. God bless you.

I cannot express my gratitude enough, omg! Thank you!!!! I've been watching all your Hypothesis Testing videos and I am now confident that I pass my exam next Thursday. I'm going to just make sure to repeat your videos until I understand the concepts well! but with your explanations I am more convinced I will pass the class, I will pass thanks to you! I wish you were my professor for every class I take !! :(

Watching it after 10 years, still worth it.

stats major here and i really love these videos. lecturers in school are teaching off textbooks that just make these concepts more complicated than it is. than you brandon!!

1) So viewers can make sure its what they want, 2) fast-forward makes it easily skip-able, and 3) connection and encouragement go a very long way for a lot of people.

You are the best! I skipped a class because I work and this video bridged the gap! Thank you so much!

Thank you SO much for posting these videos. I (as a terribly struggling statistics student) greatly appreciate you breaking everything down into not just the formula, but why it is so. All thumbs up from me!

Hi. Brandon. Im a Community medicine MSc undergraduate. I use your videos most of the time. I think you are doing a huge service. I wish your success. Post more videos also. Thank you from #SriLanka

Hello! The critical value in this case is the value our z-score (test statistic) must be beyond to reject the null hypothesis. Think of it as a "threshold for rejection." The p-value is the probability beyond our test statistic. So for a one-tailed test, if our alpha level / significance level was 0.05 (5%), and our test statistic fell right on the critical value, then the p-value would be 0.05 because that is the probability beyond the critical value. (cont.)

Beautifully explained. Made it so simple to understand. Grateful!

Thank you so much Mr Foltz. I have been struggling with my first module on statistic as I am studying via correspondence. These videos have really helped me!

THANKYOU!!! You probably get tired of hearing this, but your videos are amazing.. my professor is great, but he fell flat on the test of hypothesis chapter.... you are saving me final grade. Bless you

I am from Illinois PhD student at (SIU). I really appreciate this generous effort. keep going

Your videos are being watched in the oldest city of the world ❤️ we love you sir. God bless you

If our test statistic is beyond the critical value, then the p-value would be less than 0.05 because there is less area/probability beyond that point. If the test statistic is inside the critical value, then the p-value would be larger than 0.05. So think of a doorway. The door threshold is the critical value. If you (the test statistic) stand exactly in the doorway, p=.05. If you go beyond the doorway, p less than .05 (reject null). If you stay on this side of the door, p greater than .05.

This is a life saver. I wish you were my teacher. mine doesnt understand how to teach. Thank you. Your the first video i saw that explained that you use the confidence to get the Critical value

your positivity and clear voice really add to the great clear explanations!

omg it's finals week right now and that pep talk at the beginning of the video just about made my day and helped me destress a little. Thank you so much! i loved the video ^_^

. Must appreciate your lectures... and pace . Thank you .

Just want to stop by and say thank you again for taking the time to make these wonderful instructional videos. I have learned so much, especially from your videos.

Thank you so much for making this video! Saving my life during finals week!

Sir! You are a marvellous teacher and educator!

Why do I pay tuition for half assed BS lectures that I don't learn anything from? Like this videos and this man alone tough me statistics. Not my professor who gets payed for it! Who shows up to class with zero interest, zero preparation and rambles on until half the class is a sleep because they're already lost 5mins into the lecture! I don't like to blame others for my bad grades, which I don't because I always find ways to learn the subject and get As, but it still boggles my mind how I learn and understand better from FREE youtube videos then I do from my professors who get all the money and credit. Sorry, I had to get that off my chest. I would just like to thank Brandon Foltz my true professor thanks a lot for what you've done. I can tell you put in a great deal of work into these videos and appreciate it all.

hahaha just started an online statistics class to prepare for real college. Im excited but I have a headache now lol thanks for taking time out of your day to do this for us people!

you are wonderful Mr.Foltz thank you so much

Fantastic explanation of this concept! It finally clicked watching this video.

awesome lectures. this one really helped me with my exam prep. Thank you so much.God bless

You are the best!!!! Thank you so much!!! I don't have enough words to say thank you to you, this videos changed my life and my grades.

This is an amazing Math channel! Thankk you so much for creating this !

Thank You very much Dear professor, Really you are the super professor I have seen ever.

Many thanks from Britain

very nice explanation. you're much better than my college professor.

Thank you very much for this video Mr Foltz. Its very helpful for me while studying my Quantitative Techniques in M.com

Thank you Brandon. As always, you are the best..

Thank you Thank you Thank you!!!!! :) I am sure I will pass this course with the help of your videos!

fantastic approach!

you are lifesaver. Thank you very much for your stats videos

amazing...... eassy to understand the errors thank you so much for these vedio keep on going....... 😍

Such great videos! Thank you so much. Your videos are the best.

thank God for these videos!!!!

17.07 needs a correction I guess " sample mean to be inside the non-critical region". Thanks very much Brandon !

Dear Mr. Foltz, Please refer to time 9:13 of video. In the last point you have mentioned "It is always good to check the sample data for normality; better safe than sorry. What if the sample data not normal? Is normality of sample data a prerequisite to carry out the hypothesis test? Please elaborate. Regards, Sushant

Again Thanks for best content...

Thank you Mr. Foltz

You are amazing!

Hola señor Brandon! my professor has a postdoc and they are not able to explain this as well as you do. Thank you!!

Great Videos

Thank you for the encouraging words. So great.

I get it, Test statistics is just measure the actual sample mean is how far away from hypothesis' mean, to know the hypothesis mean is still right or not.

many thanks, you are doing a great job

i like this guy

how to get z critical value as 1.96 from z table? in z table no value crosses 1.plz send me the link how to get?

thanx millions brandon

i dont know if he goes on this later but the assumption of normality @ 30 can be wayyyyyyy off. it depends on the population distribution but if it is highly skewed like an exponential it could take 500+. like an exponential is not gonna become normal at 30. also and this is super imp it depends on the parameter under investigation. the means are pretty simple large enough sample and you can use clt but if you are making an inference on std dev it is extremely sensitive to skew and you probably wont be able to use ttest and in those cases you are going to have to use a resampling technique.

It would be great if the ppt from the video was downloadable, just to have something to print rather than taking notes for each silde. Vid was very helpful! Thanks.

Very helpful video

great explanation Brandon :)

great work

Hi Brandon, thanks for providing us with the App information by RealXY App. I have it installed on my phone and it is so very convenient. However, under "Table" there is no option for finding "Z-Critical Values. There are Chi-Square, F, Normal Standard and Student's t. Is there another App I can use to find z-critical values? It is so very convenient having an App on my phone. Thank you for all you are doing, words cannot explain my appreciation!!

awesome video

Great!! I understand now, thank you :)

Thank you so much, I have some question, If the data is not normally distributed, which test should we use

Wishing You long-life

Thank you!

Brandon, I love these videos. I just wish I could figure out what the order is. I feel like I'm throwing darts when I try to get to the right video in the overall narrative.

How would we calculate risk and benefits of Astrazeneca Covid vaccine? Everyone is explaining benefits with incidences of events, but no one has presented a paper with a null and alternative hypotheses, using e.g. a two tailed t- or z-test, and actually reject or fail to reject the null.

Hello. In what videos previously did you talk about the standar error of the mean?

Great

Thank you sir

You saved me ;-; Thank you

Love the quote! #nontraditionalstudent

What if our sample's mean is on the critical value. Do we say the test is inconclusive or we just fail to reject ?

95% of the world are grateful to you because they can't afford textbooks.

At 17:25, why is the Z score calculate using the standard error? I read that you divided by the population standard deviation. Could someone clarify this for me please?

what is the relationship between P-value and critical value?

thumbs up

I didn't understand where come from the values for Z=|1.96|, I hope to get some help on that.

Update!! I found the z-critical under Standard Normal. What got me initially is that it calculates 2-tail, rather than one. So the probability entry is 1-(alpha/2).

I love you

Hi Sir, how can i contact you, i have many questions about statistic, i have exam and i need help

It would be helpful if you told people how to find the critical value -_-

thank you T_T

Brandon why is this video so long.

If you speed the video, he sounds like Kermit the frog

Dude, get on with it. Why do you need a 2 minute intro?