Random Variables
A number tied to a random outcome.
What is a random variable?
Binomial settings need a fixed number of these.
What are trials?
Expected value is the long-run what?
What is average?
When random variables are added, the means do this.
What is add?
The shape of a normal distribution.
What is a bell curve?
A random variable with countable values
What is a discrete random variable?
The two outcomes in a binomial trial.
What are success and failure?
If every value goes up by 5, the mean changes by this much.
What is 5?
When random variables are subtracted, the variances still do this.
What is add?
Mean and standard deviation of the standard normal curve.
What are 0 and 1?
All probabilities together must equal this.
What is 1?
Formula for binomial mean.
Multiply every value by 2... standard deviation changes by this.
What is 2?
Needed to combine standard deviations correctly.
What is independence?
Score showing distance from the mean in standard deviations.
What is a z-score?
A common graph for discrete probability distributions.
What is a histogram or probability distribution table?
Formula for binomial standard deviation.
Answer: What is σ= square root np(1−p)
If expected value is -$2, players usually do this.
What is lose $2?
For independent variables, variance of X + Y equals this.
Var(X)+Var(Y)?
z-score formula.
z=σx−μ?
Another name for the mean of a random variable
What is the expected value?
Distribution for trials until first success.
What is a geometric distribution?
Expected value formula.
What is μX=∑xP(x)μ=∑xP(x)?
If means are 10 and 7, what's the mean of X − Y?
What is 3?
About 68% of data falls within this many standard deviations.
What is 1 standard deviation?