The Central Limit Theorem, Part 2 of 2

[kzawy]

nice video, thank you! :)

[TheToshme]

wonderful presentation which allivate my problem on central limit theorem.over all well presented

[diegoramos27]

Very good video but i think is 1- A, not 1-0.5

[ranagan9]

how did you get that value of A? it seems unnecessary. when i looked up 0.74 in the "areas in tail of normal distribution" table the value 0.74 yields an area of 0.2296. is this just a coincidence or another way of doing it?

[Cyanide89]

THANK YOU SO MUCH! You... you genius man you.

[GeneralGibbons]

1:47 *applies, not applys

[Lutemann]

Sorry, General.

[GeneralGibbons]

Its ok, just a friendly grammar correction

[Ishayau]

First video Great!

In this video, you complicated things to much. You could have approached the problem from a risk point of view (Alpha level of 5%)

[yanzipunkstar]

Yh ur right!! actually its not the tables fault.. i looked for phi of 0.2704 in the table.when i looked for 0.704 it said 0.7704..then i have to substract it from 1.

Our charts are different i presume.mine`s always above 0.5

[Lutemann]

I use the chart that gives you the area from th mean to any point on the X axis. I do this way because the table is only one page, because that's the way you do Chebychev's problems and that's the way students do Empeirical Rule problems. Why confuse students.

[yanzipunkstar]

Actually the probability of getting more than 98 is 0.3936

that is 39.36 % which is far from 23 % tho i know its an approximated figure.

I got this figure from the normal distribution table.

[Lutemann]

I think you need to check the table. I just did and my figures are correct.

[08SJF08]

very well explained!

[pignition]

It's great, I also felt the things clicking in my mind. thank you

[Talian1]

Great tutorial, I could feel things starting to click. Thanks.

[vs10]

thank you. makes much more sense than simply reading a textbook!

[buysellgoods]

...i wish you replaced our stupid ass tutor! great video.

[Sameer3292]

yesssss !!! i solved this problem on your first video and the answer came out to exactly 23%. :]

[kit1957]

I am taking online classes through a university and it can be extremely difficult to learn this stuff by just looking at the examples in a book. The way you explain as you go makes so much sense. I can almost detect the room brightening when that light bulb goes on in my head. THANK YOU!

[Xxshadow200xXXD]

nice thx

[iamgregor4e]

Very nice tutorial!

Greetings from Germany...

[advanup]

i know he was using a different Z table. the truth is the z table he used only gives the area to the left of a given point, and that's why his answer was .7704. anyways according to your question his answer is not correct due to the fact that he didn't subtracted from 1.

[advanup]

this is for krivivy what you found is the area to the left of 98.85 and what the question is asking for is the area to the right of 98.85 so therefore 1-.7704=.2296. Lutamann is correct

[Lutemann]

Krivivy was using a different Z table. I use the more simple, one page table that gives |Z| from the mean.

[krivivy]

.7704, not .2704.

[Lutemann]

The area under the normal curve from 96 to 98 which is .74 standard deviations is .2704. The total area under the curve up to 98 is .7704.

[lambofpaul]

thank you! this was very helpful

[SurfSeeker22]

Im confused on how you get the .5 ?

[Lutemann]

You have to be familiar with finding the areas under the normal curve. The normal curve is symmetric about the mean - 50% is above and 50% is below. If you wish to find the area in the tail of the curve, you subtract the area up to the tail from .5.

[Lutemann]

If you have a sample size less than 30, you use the t distribution instead of the z distribution. Actually, you can use the t distribution for any sample size, large or small, but when the n>=30, there is little difference between the two distributions.

[800382914]

Hi ,

I would like to ask question.

1. Why is it that you mention the number '30'

Why not say 50 or 100 ?

2.What happen if the sample size is below 30?

say for example 20 , does the CLT still holds .Howe do we solve if the sample size ,n is less than 30?

Thank You

[Jebrone]

THANK YOU! this made me understand what the Central Limit theorem is IMMEDIATELY! I feel like Im getting ripped off in my class since the teacher doesnt explain this stuff. Other than that ill answer the number man over here.

1 It seems random to me as well.

2 It will not, because there will be to little amount of numbers!

[zasabiibasaz]

2 ez

i aced stats

try some complex analysis

[Lutemann]

I'm working my way up. I'm trying to get others to do this, but no one has the time.

[zasabiibasaz]

well spend less time on u toob fool

ahhahaah jk at least ur watching something learningful lol

r u a math major they own all ya no

[nydaa]

ma koji je ovo kurac...