Studied by 3 people
Looks like no one added any tags here yet for you.
random variable
a variable whose value is a numerical outcome of a random phenomenon
discrete random variable
a countable number of possible values
how do you find the expected value of a discrete probability distribution (or the mean)
multiply each possible value by its probability then add all products
how do you find the variance of a discrete probability distribution
subtract the mean from each possible value, square that, multiply that by the individual probability of that value, then add all those values together
how do you find the standard deviation of a discrete probability distribution
take the square root of the variance.
what does the linear transformation rule for means say
if x is a random variable and a and b are constants, then the mean of the transformed variable a+bx is given by E(a +bx) = a + E(x)b
what orders of operations can be done with means
the means can be added, subtracted, or multiplied together but cannot be divided
if x and y are INDEPENDENT random variables, what order of operation can you do with variances
the variances can ONLY be added
what is the rule for the variance of a transformed variable
given the equation a +bx, you can transform the variance with the equation Var(a + bx) = b²Var(x) where b is the slope
continuous random variable
takes all values in an interval of numbers, infinite number of outcomes
how to calculate the probability of a continuous random variable
take the area under the density curve
what is a the probability for any individual outcome of a continuous random variable
always 0
what is a uniform curve
A type of probability distribution where all outcomes are equally likely within a given interval (both height and length are 1)
