EOYR Unit 4 vocab Flashcards
probability this AND that . Add or multiply?
MULTIPLY
What is “mutually exclusive?”
same as disjoint
RAND VARIABLE: X has mean y and standard deviation of z. A has mean b and standard deviation c. Find: Mean, SD and VAR of: 3X
mean: 3y SD 3z var 9z2
What type of probability when you are looking for exactly 5 or less successes in twelve attempts?
binocdf(12, p, 5)
Give three examples of independent variables
- Being tall and having a high GPA2. If it is snowing and whether it is a Thursday or not3. Whether a person likes pizza and their gender(notice, knowing one bit of information does not impact the likelihood of the other being true also)
How do you find mean and sd of probability model?
put values in L1, probabilities in L2, and run “1-var stats L1,L2” and you get it!
what is n! ?
it is “n factorial” example: 5! = 54321= 120. tells you how many ways you can arrange n objects.
What is the expected value?
The mean of the random variable. What you’d AVERAGE if you played the game A LOT!!!!!!!!!
What is probability first success is on 7th try?
qqqqqq p (q^6*p). (this is a GEO prob)
binopdf
(n,p,x). Probability of exactly X successes in N trials. (PARTICULAR probability)
What is the “mean of a random variable?”
The expected value. sum of probs times values
RAND VARIABLE: X has mean y and standard deviation of z. A has mean b and standard deviation c. Find: Mean, SD and VAR of: 5A
mean: 5b sd: 5c var 25c2
What type of probability when you are looking for more than 5 successes in twelve attempts?
(6 or more)
1 - binocdf(12, p, 5)
what do we call it when events are not associated?
independent
What type of probability when you are looking for at least one success in twelve attempts?
1 - p(NONE)
not zero, not zero or less
1-binopdf(12, p, 0)
How to find likelihood of being pregnant, given the test says you are? (tree)
Split population by %pregnant and %not who take test, then each of those into what test says. Then look just the groups that the test said pregnant. Then find: %pregnant/(total percent in both groups).
RAND VARIABLE: X has mean y and standard deviation of z. A has mean b and standard deviation c. Find: Mean, SD and VAR of: X + X + X
mean: 3y sd sqrt (3z2) var 3z2
How to find P(at least 1)?
1-P(none)
RAND VARIABLE: X has mean y and standard deviation of z. A has mean b and standard deviation c. Find: Mean, SD and VAR of: 3X + 5A + 12
mean: 3y+5b+12 sd:sqrt (9z2 +25c2) var 9z2+25c2
How can we use Pascal’s Triangle?
To find probability of x successes in K trials.. BINOMIAL BABY!!!
what does binomial model tell us about?
exactly x successes in K trials. What is likelihood of exactly 3 heads out of 13 flips?
what is the law of large numbers?
states that in the long run.. (NOT SHORT RUN) The relative frequency settles down to true probability. (you’ll have 50% heads after an infinite number of coin flips with a fair coin)
when can you expect the first success? (mean of GEO) if ther3 is a 30 percent chance?
1/p? or 1/.30?. Which is 3.333 so around the 3rd or 4th try.
This tells you, on average, when the first success will occur
What is the area under the normal curve?
1 or 100%
what is probability?
THE LONG RUN RELATIVE FREQUENCY!!
What type of probability when you are looking for exactly 5 or more successes in twelve attempts?
(more than 4)
1 - binocdf(12, p, 4)
can disjoint events be independent? EXPLAIN
NO.. If they are disjoint then knowing one tells you that the other couldn’t happen so they are always NOT INDEPENDENT? or DISJOINT EVENTS ARE ALWAYS ASSOCIATED!!
what is pythagorean theorem of stats?
st dev of combined model is: sqrt(st dev squared + st dev squared) or more if you combine more?