hey sir just two technical queries please when you are writing the critical regions at 4:57 1. can you write it as little x bar instead of big x bar? 2. can you do greater than or equal to (as opposed to just greater than) when writing the critical regions (and same for less than)? because it doesnt matter as its continuous?
No, big X bar is referring to the whole set of possible x bars - small x bar is a specific sample mean. Big X bar is the entire set of sample means - a subtle but important difference. Yes, it doesn't matter for continuous - the convention is to just use < and > though!
Sir, at 13:22 is the reason why we do the variance as 0.015^2/50 because we are interested in the sample mean? If this was not to do with means, would it be just the SD squared?
Hey sir, how do we differentiate between questions where we’re using critical regions to test the hypothesis using inverse normal function or where we only use the cumulative normal function?
Hi sir I have a question about the z values, I don't remember where but sometimes when you are working out the X values knowing the z you can have them as negative. Do you know when you can use this instance?
The z values would be negative if the x values were below the mean - this is because the mean for the z values is 0, so if it were less than the mean, we get a negative. Hope that helps!
HI, Do we need to learn both methods for hypothesis testing with the normal distribution? Is it ok if I dont learn the critical region method for the normal distribution?
I should think you’ll be OK with the normal distribution - but be warned they sometimes ask for critical regions, in which case you’d need to know this method!
how come when 0.587 > 0.5855, we reject the H0 ? i thought normally in hypothesis testing, we accept H0 as higher probability that it has occurred due to chance?
This is a critical region question, where the numbers you have shown aren't representing probabilities - instead, they are represent the values along the x-axis, i.e. the variable. If the value goes into the critical region, i.e. it is bigger than that value, then it has a smaller probability than the significance level, and so we reject H0.
my teachers been off because of covid so thank you for your constant hard work with these! these videos are amazing 😩
hey sir just two technical queries please when you are writing the critical regions at 4:57
1. can you write it as little x bar instead of big x bar?
2. can you do greater than or equal to (as opposed to just greater than) when writing the critical regions (and same for less than)? because it doesnt matter as its continuous?
No, big X bar is referring to the whole set of possible x bars - small x bar is a specific sample mean. Big X bar is the entire set of sample means - a subtle but important difference.
Yes, it doesn't matter for continuous - the convention is to just use < and > though!
@@BicenMaths Thanks so much- I will make a note of it
Sir, at 13:22 is the reason why we do the variance as 0.015^2/50 because we are interested in the sample mean? If this was not to do with means, would it be just the SD squared?
Yes, that is correct!
Hey sir, how do we differentiate between questions where we’re using critical regions to test the hypothesis using inverse normal function or where we only use the cumulative normal function?
It will tell you if you have to do critical regions clearly, and if not you have a choice of which method to use!
thats me done with learning stats! thanks for the great videos sir. icl im terrified of mechanics I've heard its hard
Noooo it’s the best bit of maths! I hope my videos will help make you love it.
@@BicenMaths hope so :)) i actually really enjoyed the second part of statistics even though its slightly harder
@@rev0cs Agreed! Second part is much more interesting
Question 8 also tests the critical regions
for 18:20 isnt it not inside the critical region rather than being in it?
Careful - 0.587 is bigger than 0.585!
Hi sir I have a question about the z values, I don't remember where but sometimes when you are working out the X values knowing the z you can have them as negative. Do you know when you can use this instance?
The z values would be negative if the x values were below the mean - this is because the mean for the z values is 0, so if it were less than the mean, we get a negative. Hope that helps!
@@BicenMaths Thanks alot.
HI,
Do we need to learn both methods for hypothesis testing with the normal distribution? Is it ok if I dont learn the critical region method for the normal distribution?
I should think you’ll be OK with the normal distribution - but be warned they sometimes ask for critical regions, in which case you’d need to know this method!
how come when 0.587 > 0.5855, we reject the H0 ?
i thought normally in hypothesis testing, we accept H0 as higher probability that it has occurred due to chance?
This is a critical region question, where the numbers you have shown aren't representing probabilities - instead, they are represent the values along the x-axis, i.e. the variable. If the value goes into the critical region, i.e. it is bigger than that value, then it has a smaller probability than the significance level, and so we reject H0.
how come for binomial we add one to the upper value but we don't do that for normal ?
Because binomial is discrete, and normal is continuous. So continuous just means that we can say it's above that exact value!
Please be my teacher
I am your virtual teacher!
@@BicenMaths I've been watching your videos the whole year. You taught me better than my teachers tbh
I hope it goes well for you with your exams! Good luck!
where do you get 0.587 form sir ?
It's the value we are testing in the question :)
don't you have to use rho instead of mew tho?
No - you use rho when doing hypothesis testing for the correlation coefficient, r. We use mu here!