@aznboi4981 first of all standard deviation is the square root of variance. expected value is what will happen in a long run like the average amount in a long run. First of all to use binomial it has to be binary = success and failure. it needs to be independent. The question need to say specific amount of number . the trails are fixed in binomial. pdf is when you find the exact number they want. cdf is finding all the number up to the number they want including the number they want you. geometric is all you are finding is first success. I am sorry i am bad at explaining things but hope you understood a little.
@aznboi4981 I can help you with the probability.
An expected value is essentially the average value. In other words, to calculate it, it is the sum of the values times the probabilities of those values. This formula will be given on the exam. When combining random variables, to get the sum of the means, simply add them. When finding the difference, subtract.
Now, for variances, you need to understand the Pythagorean Theorem of Statistics. This is the idea that, when finding the standard deviation of multiple random variables, you add their variances and then take the square root of that sum. Regardless of finding the sum or difference of standard deviations, you ALWAYS add variance since you’re increasing variation.
Before using either geometric or binomial distributions, there are three things you must check before proceeding: binary outcomes (a success or failure), a constant probability of success, and independence. The difference between the two distributions is that geometric is for finding the probability of a success occurring at an nth trial, while binomial is for finding the probability that the success outcome occurs x times out of n trials. Pdf is used for exact trial/number of successes, while cdf is for any number of trials/successes at or below the maximum number. For instance, if binomcdf(6,0.5,4), then 6 is the number of trials, 0.5 is the probability of success, and 4 will allow you to calculate probability that the success outcome will occur 0, 1, 2, 3, or 4 times out of all trials.
I hope this helps! Good luck tomorrow.
Wish everyone the best of luck tomorrow.
Last AP test…fingers crossed for a tolerable test
Idk I heard the AP tests are hard one year than easy the next… That scares me BC all the kids last year walked out super confident that they did well
Yeah I did the 2015 FRQ for practice…and it was easier than I expected.
I hope the FRQs tomorrow are similar
@lightblaze259 Thank you SO much! Much appreciated. 
I know this is late but can someone explain what pooling is and when to ever use pooling?
@ADA110 I don’t think you need pooling for AP Stats BC my teacher told us to ignore the calculator function.
Could anyone explain to me last minute what “power of the test” means?
Ok as of now Im planning to fail this exam on purpose because if I get credits, I have to take a math class as an elective instead of my core classes. Stat for my college is a prerequisite anyway so it wouldnt do anything but bump me to a higher class that binge self study hasnt prepared me for.
Power of test is 1-beta and beta is type two error
Finished! Yayyyy
@lulu0207 Did you find frq or mc hard?
Just got out. I’m really happy with myself. The MC was so time-lenient and straightforward, so really easy overall. FRQ was also good, except I had to leave the last parts of the last two questions blank (I thought they were tricky). But nevertheless, it was easy. I anticipate a 5.
So… Did anyone put whether that one thing was appropriate or not
Also, did anyone else find Q6 uncomfortably easy?
I agree that the test was pretty easy, but that made me more nervous haha :))
Mannn that test was superrrrr easy. Especially the frq. Esssspeecially the question 6. I didn’t expect 6 to be that easy. Either i got all frq questions wrong or it was just thattt easy
@holyground I said that it wasn’t appropriate for an interval
What raw score is needed for a 5? And is there a formula that gives you a rough estimate of your score?