Interview #2 Material

what is a discrete random variable

quantitative variables that have a countable, but possibly infinite, number of responses

what is a continuous random variable

random variables that can take on an uncountable number of values

what is a distribution

a way to describe the shape of a probability curve

what is a discrete probability distribution

a description of the frequency or relative frequency of each of the classes based on experimental units

what is an expected value for a discrete probability distribution

a representation of a mean, but only over many, many trials

what is the standard deviation for a discrete probability distribution

a representation of the data and how its spread out across the distribution

what is a uniform distribution

a distribution where all the probabilities of being near a value is the same

what is a NORMAL distribution

a continuous distribution where the shape is specific to a bell shape

what is a point estimator

a single point that is used to make an inference

what is an error of estimation

the likely value of the difference between the estimate and the true value of the parameter

what is an unbiased estimator

when the mean of a sampling distribution is equal to the parameter in question

what is a biased estimator

when the mean of a sampling distribution is not equal to the parameter in question

what is the standard error of a statistic

it is what we call the mean and standard deviation for sampling distributions specifically

what is a sampling distribution

a distribution where the values come from a large set of samples, and we look at a specific statistic of these samples

what is an interval estimator

an estimation of a parameter using an interval

what is a margin of error

half of the width of the confidence interval

what do we mean when we talk about confidence (confidence interval)

over many trials, % of results that match the parameter to the interval

what do we mean when we talk about significance

over many trials, the probability that a randomly selected trial will not have the parameter on the interval

what are degrees of freedom

sample size minus one