AP Stats Test Quick Review: Random Variables

This is a quick video that goes over random variables, what they are, how to find the mean and standard deviation of a random variable, how to transform and combine them.

[geenstagni]

I'm so surprised to see the criticisms in the comment section because I thought this video was wonderful! Thank you Michael!

[reiweather]

Great video! This was an easier chapter than I thought

[SupermodelGaming]

Great video! If only my professor knew how to fucking link the correct videos that are relevant to questions he assigns on the homework.

[ayandas]

Hi Mr. Porinchak, thank you for these review videos! I had a question about transformations to the standard deviation. When do you square the b value inside the square root and when do you not square it? As I understand it, you always square the sigma value.

[makisekurisu]

Coronavirus: MC we don't do that here

[michaellewis]

I feel like often times you don’t justify something when it’s really easy to justify. With the variance being added both times, it’s obviously that it has to do with how the mean spread is effected, which it’s not whether you add or subtract it’s the same linear adjustment.

[michaellewis]

7:00 also the data is clearly skewed left..

[michaellewis]

Also sorry for using your comment section as a notebook

[michaellewis]

For average you didn’t really explain it satisfactorily. You should’ve said that we know that people definitely buy above and below this value, and based on how far below and above, we get this number.. It is what happens when people choose discrete values indivisible by the sample size.