Algebra II: Mean and Standard Deviation

[StinaBobina56]

None of your videos are working for some reason... they wont play passed like 3minutes

[bjunt4prez]

thanks, helped out a lot !

[QueenBeatlesWings]

if given a question like 'invent 2 data sets, each with 7 values, so set A has a greater std. deviation and set B has a greater interquartile range"? (but not given any numbers or other tips) how would you decide if a set of data had those things

[Crakamatt]

Does this apply to Stats?

[FireSign27]

The formula with (n-1) as the denominator is the estimate deviation, you use it with sample data.

[b1g1freeagain]

hmm i thought the standard deviation has the denomintaor as (n-1). it should b 54/4 = 13.5 square root of that is 3.6 the closest answer would be 3.3.

[jenngreff]

Your n-1 is used in computing the mean, not the standard deviation.

[uz4ir12345]

started stats 3 days ago

hope it goes all well

nice vid

[bradkey98765]

hang on aren't you working out the RMSD (root mean squared deviation) not the standard since they have changed it so it's now the root of sxx over n-1 ... and i think the variance is now the sum of the squared difference from the mean divided by n-1. Well that's what I'm suppose to know for my statistics as paper tomorrow....

[khanacademy]

When you divide by n-1 instead of n, you are figuring out the sample variance, not the population variance. I'll do a whole video on this.

[bradkey98765]

Ah thank's for clearing that up for me :D and thank you sooo much for carrying on making video's i've been watching them for around 2 years now :O, I had my S1 paper last friday and think i did pretty well can only recall going wrong on one question which was work out E(X) and the variance from a probability table labled r 1 2 3 4

P(x=r)0.65 0.05 0.05 0.25

Still not to sure how to get the variance from a probability table do you have to use E(X) to find the mean?

[payasitopimpim2002]

great my friend ..a fan from here latinamerica.....

[Beefstew2011]

2nd comment

I win.

[gamemaster014]

wow lol i was wondering when you were going to post problem 79 and 80