AP Statistics Full Unit 9 Summary Video - Inference for Slope

This video is a full summary review of Unit 9 for AP Statistics over inference for slope of a regression line.
For more exclusive summary videos, study guides, practice sheets and much more to help you in your AP Statistics class and on the AP Statistics exam check out the Ultimate Review Packet for AP Statistics. It has everything you need to review what you are learning in class and prepare for the AP exam. Check out a free trial with the link below: www.ultimatereviewpacket.com/...

[@SaadKhan-wr7bk]

Hellow sir. I just want to give u my appreciation, my Ap exam is on May 7th 2024, starting this Ap i was very nervous and extremely bad at statistics thus making me scared that i may not even get a 3 at the point where i was, so i had almost given up and potentially wasted my parents money for the Ap but then a friend referred me to you and sir...May god bless my friend bcz now that i came across u and understood eveything, i think there is a chance of getting a 5 now, May Allah bless you, ur a true hero, changing students lives, after my Ap is done i will refer to anyone i know struggling in Ap to you❤.

[@mporinchak]

You have no idea how much I appreciate this comment. I am so glad to hear that my videos changed your grade and attitude around about AP stats. I hope you get that 5 on the exam!!!

[@SaadKhan-wr7bk]

THANK YOU SIR ❤, AND HOPEFULLY I WILL​@mporinchak

[@DB77111]

Are you an international student

[@untitled_008]

Your videos have truly been lifesavers - I'm sure especially for us self-studiers. Thanks for all the helpful videos to overcome the AP statistics exam ahead of May 7th.

[@mporinchak]

You're very welcome! Best of luck on the exam.

[@jakubehrlich6682]

I have a test tomorrow and you saved me thank you

[@milkypooo]

I LOVE YOU MR PORINCHAK YOU HAVE NO IDEA HOW MUCH YOUR VIDEOS HAVE SAVED ME. THANKYOU!!!!!

[@mporinchak]

Awesome glad I can help!

[@diasridhar]

Thank you Mr.Porinchak!! Extremely helpful! The URP too!

[@brittricci2058]

Thank you so much for these videos!

[@historystuff1114]

Thanks!

[@Tutorllini]

Keep up the great work Michael!

[@mporinchak]

Thanks, will do!

[@eileenlee9133]

Thank you so much Mr. Porinchak you are saving my life right now !!!

[@seantanimura5164]

All your videos have been awesome and super helpful. Ready tor rock that exam tomorrow!

[@mporinchak]

Good luck!!

[@MathYoda]

The goat. Was gonna fail the AP exam before your reviews, but now I think I can get a 5.

[@mporinchak]

So awesome that I hear I helped you turn things around. Best of luck on the exam

[@jillian-fv6ep]

Thank you so much Mr. Porinchack! Quick question, what is the difference between z-test, z-interval, t-test, and t-interval? Thanks in advance!

[@mporinchak]

To keep it simple. Z interval and z test are for inference for population proportions. T interval and t test are for inference for population means.

[@parvanehbehnam9424]

Hey Mr. Porinchak, is that okay if we simply use the features on the calculator and write what we input into the calculator? Like the test and interval features. Thanks

[@agustya8889]

I was just wondering, is the curve on the ap stats exam different each year? If it is, do you think it is going to be higher this year?

[@mporinchak]

It is hard to predict and changes every year. Once the raw scores are in usually around the top 11-13% get 5's and then down the line, so it depends on those raw scores.

[@avi5542]

Hey Mr. Porinchak, on the AP exam will it tell you to construct a test or something, if we do have to run through all the steps of significance and confidence?

[@mporinchak]

If the questions is to create a confidence interval or to determine if there is significant statistical evidence you will have to do all 4 steps, name the procedure, check conditions, build the interval or find the p-value, interpret and conclude. Sometimes a question will say assume all conditions are met and therefore you wont have to check conditions.

[@user-gh7po5bn6t]

Can you please explain how the sample size being less than 10% of the population ensures independence? If the sample size is bigger, it would be closer to population size making the calculations even more accurate right? What does it mean when we say that the sample size n being less than 10% of the population helps independence?

[@SanjulaJakati]

It is so that you can treat that specific test which you are checking all of the conditions for as its own test. If you had a larger sample (because you are deriving that sample from a population) then your calculations would be just similar to the population stuff. It also helps prevent bias...... (someone has to fact check me on all of this)

[@mporinchak]

When we do statistical inference it is all about the sampling distribution which is a model of all possible sample statistics from all possible samples of the same size taken from the same population. In that model, we know the possible sample statistics will vary, but they must vary independently of each other for the standard deviation (which measures that variation) to work. If we sample with replacement this is promised to us. But typically we sample without replacement which violates independence between samples. BUT this is where the 10% rule comes in. As long as the sample size is under 10% of the population, yes we are still technically violating independence, but the change is negligible so we don't worry about. Hence why we check the 10% condition. Now if the problem is experiment based with random assignment of subjects to groups we naturally have independence and do not have to check this condition. Hope that helps!

[@mambo5431]

@@mporinchak this might be a bit dumb but, if a sample size is lets say exactly 10% of the population, and replacement is NOT done, wouldnt it mean that there can only be a max of 9 other samples of the same size that make up the sampling distribtuion?

[@eviefrogs777]

I'm going to explain this using the example of choosing colored gumballs. Let's say there's 100 gumballs in 5 different colors and the probability of getting each color is 20%. All samples with this condition are without replacement, if there is replacement it's automatically independent. If you take a sample of 5 gumballs (less than 10%) then that sample doesn't affect the overall probability of getting each color enough for it to matter and we can say it is independent. If we took a sample of like 50 gumballs though, the probability of each color will change bc the mix of gumballs left in the machine would be completely different mix with different proportions of colors than what we started with so each individual observation would not be independent.

[@abdallahsaleh1359]

@@mambo5431 btw the 10 % condition says that the sample size must be less than or equal to population size to assume independence if sampling is done without replacement. So you could indeed assume independence if sample size is exactly equal to 10% of the population size. Hopefully that answers ur question!

[@ddozzi]

goat