Thumbs up if you didn't know that the TI calculator had the 2nd-Ans function... even though you've owned that same calculator since 9th grade highschool.
I'm confused--I thought the sigma was supposed to represent the population average and sigma_x-bar the standard deviation of sample means of size n taken from the total population. But then wouldn't that mean that n is not 50, because that would just be taking the whole population as our sample?
These videos are great, though I think I see an issue here.
.7L was already the standard error of the population mean...or sigma/sqrtN, where N is large, where sigma is the stdev of the population.
Therefore, it seems incorrect to divide this value again by sqrt50, since this would yield sigma/(sqrt(N*50).
In other words, it doesn't make sense that the standard error of the sample mean would be smaller than the standard deviation of the population mean. Rather, it should approach it as n inc.
I understood the problem completely thank you very muh.
As a side question: couldn't we solve the problem by just multiplying the mean and standard deviation by 50 so we would get a normal distribuiton of N(100,35) and calculate P(X>110) ?
the sampling distibution of 50 samples (n=50) brings up a distribution almost the same as normal distribution. we also have the standard deviation of the sampling distribution as .7 / sqrt(50) almost equal to .1. we also know the mean is 2.0. from that point on, why do we not consider 2.2 to be 2 standart deviations away from the mean and just apply the empirical rule ((1-95%)/2=2.5%)?
thanks in advance for a probable answer. thank you teacher :)
the sampling distibution of 50 samples (n=50) brings up a distribution almost the same as normal distribution. we also have the standard deviation of the sampling distribution as .7 / sqrt(50) almost equal to .1. we also know the mean is 2.0. from that point on, why do we not consider 2.2 to be 2 standart deviations away from the mean and just apply the empirical rule ((1-95%)/2=2.5%)?
thanks in advance for a probable answer. thank you teacher :)
Excellent. - And now... the probability that the world is facing a currency fight between nations...and the probability for US to get out save from this fight.
Good job, bro. I was once teaching this to my dumb ex wife (whose major was accountancy). And she didnt get a damn thing out of me. Maybe because I am engr :D
some sort of fighter jet outside...lets just hope they dont come back..
LMFAOOO khan academy <3 <3 :)
Killuminatismd 1 week ago
Thumbs up if you didn't know that the TI calculator had the 2nd-Ans function... even though you've owned that same calculator since 9th grade highschool.
NeftaliPR 2 weeks ago 2
i want to sacrifice my statistics teacher instructor please murder his ass
TheHotpinklollipop 1 month ago
I love you bro. You saved my life in physics and now you're doing it in stats <3
AlDumbrava 2 months ago
STFU and just show us how to do the problem.
roxulerz 2 months ago
Ti 83/84 command:
normalcdf(-999, 2, 2.2, 0.7, 0.7 / √50)
tom12435424 2 months ago
Thank u so so so so much!!!!
hugeworld28 2 months ago
I am in shock in awe due to the awesomeness of your teaching abilities.
As a sacrificial gesture, I offer you my ex girlrfiend.
TeKNiQ50 3 months ago 7
you are a genius!
cuiyan2222 3 months ago
Awesome!!!
NLSVTN 4 months ago
What's the reason to do a sample distrubution when you have the population as in this case?
jonatand87 4 months ago
Hmmm helpful :-)
28VS 6 months ago
JUST TELL ME HOW TO ENTER THAT IN MY TI-84 PLUS.
Romanflight 7 months ago
thank you so much for loading this video!!! it makes way more sense now because my professor had me so confused.
fullertonstreet 7 months ago
I'm confused--I thought the sigma was supposed to represent the population average and sigma_x-bar the standard deviation of sample means of size n taken from the total population. But then wouldn't that mean that n is not 50, because that would just be taking the whole population as our sample?
addemfrench 8 months ago
Sal Khan - please continue doing what you're doing, you are reaching out to more people than you can even imagine. Thank you so much.
Intuitivism 10 months ago
This has been flagged as spam show
i so damn like ur interpretation of stats, it's better than my lucture,hooooooooo
2013CHUCK 10 months ago
i so damn like ur interpretation of stats, it's better than my lucture, hooooooooo
2013CHUCK 10 months ago
may anyone tell me where i can get a calculator software like that? i really need one
vibol03 1 year ago
fantastic
mitomke 1 year ago
khan! love ya! you just saved me! XD
linkinshirley 1 year ago
This has been flagged as spam show
These videos are great, though I think I see an issue here.
.7L was already the standard error of the population mean...or sigma/sqrtN, where N is large, where sigma is the stdev of the population.
Therefore, it seems incorrect to divide this value again by sqrt50, since this would yield sigma/(sqrt(N*50).
In other words, it doesn't make sense that the standard error of the sample mean would be smaller than the standard deviation of the population mean. Rather, it should approach it as n inc.
sportsfan331 1 year ago
Comment removed
sportsfan331 1 year ago
I understood the problem completely thank you very muh.
As a side question: couldn't we solve the problem by just multiplying the mean and standard deviation by 50 so we would get a normal distribuiton of N(100,35) and calculate P(X>110) ?
Valem0r 1 year ago
@Valem0r you wouldnt get a normal distribution if you multiplied by 50. you only get a normal distribution from the CLT.
apollo3301 11 months ago
This has been flagged as spam show
hello,
i didnt get one point.
the sampling distibution of 50 samples (n=50) brings up a distribution almost the same as normal distribution. we also have the standard deviation of the sampling distribution as .7 / sqrt(50) almost equal to .1. we also know the mean is 2.0. from that point on, why do we not consider 2.2 to be 2 standart deviations away from the mean and just apply the empirical rule ((1-95%)/2=2.5%)?
thanks in advance for a probable answer. thank you teacher :)
abrekchc 1 year ago
hello,
i didnt get one point.
the sampling distibution of 50 samples (n=50) brings up a distribution almost the same as normal distribution. we also have the standard deviation of the sampling distribution as .7 / sqrt(50) almost equal to .1. we also know the mean is 2.0. from that point on, why do we not consider 2.2 to be 2 standart deviations away from the mean and just apply the empirical rule ((1-95%)/2=2.5%)?
thanks in advance for a probable answer. thank you teacher :)
abrekchc 1 year ago
you sir truly are my hero.. My teachers in college unfortunately are horrible!!! You make things so easy to understand!!!
thanks
Gtrplyr1 1 year ago
wish i had these statistics videos one year ago >.< ... ahh well these statistics videos are great and a great review :D thanks for uploading this
VSpectrum 1 year ago
Comment removed
doriangrae 1 year ago
Thanks again Sal!! You are such a good teacher!
jazerazo 1 year ago
Fun fact: the 1st standard deviation is the point of inflection on a bell curve (Sal's drawing is more just a hill)
etzel33 1 year ago
Excellent. - And now... the probability that the world is facing a currency fight between nations...and the probability for US to get out save from this fight.
norwayte 1 year ago
Comment removed
norwayte 1 year ago
stats hells ye!
Cagebreaker21 1 year ago 3
Yes! I'm so excited to see a statistics video from you in my subscription box.. you have a way of explaining statistics like no other.
The picture of an extremely skinny 50 cent in the ad kind of freaked me out throughout the whole video. He's piercing my soul
mollzz 1 year ago 5
That's a lot of dudes for a nature trip. What kind of nature trip is this =/
Jackbox55 1 year ago
Good job, bro. I was once teaching this to my dumb ex wife (whose major was accountancy). And she didnt get a damn thing out of me. Maybe because I am engr :D
freesoul2005 1 year ago
hey you still have that cliff hanger on the currency series going, don't you forget to conclude that! We are waiting!!
SalsaTiger83 1 year ago