Unit 4: Probability Distributions

Question 1

what is a random variable?

Answer 1

a value that can have any value within a range. X denotes the random variable while x denotes all the possible outcomes of X
ex. X = # rolled with die and x = different value for the 6 possible outcomes

Question 2

what is a discrete variable?

Answer 2

a variable that can have only finite and distinct values within a range
ex. the # of phone calls made by a sales person must be an integer

Question 3

what is a continuous variable?

Answer 3

a variable that takes all real (infinite) values within a range
ex. the length of time one spends on their cell phone since it can be measured in fractions of a second

Question 4

what is probability distribution?

Answer 4

a function that gives the probability of all possible values of a random variable and is denoted by P(X=x) or just P(x) for short

Question 5

what is a probability histogram?

Answer 5

a graph of probability distribution in which equal intervals are marked on the horizontal axis and the probabilities associated with these intervals are indicated by the area of the bars

Question 6

what is binomial distribution?

Answer 6

a specified number of independent trials in which there are only 2 possible outcomes, success or failure. the probability of success is the same in each trial