6.1 Discrete Random Variables

Question 1

random variable

Answer 1

a numerical outcome of a probability experiment

Question 2

discrete random variables

Answer 2

random variables whose possible values can be listen (e.g. number that comes up on the roll of a die, number of siblings a randomly chosen person has)

Question 3

continuous random variables

Answer 3

random variables that can take on any value in an interval (e.g. the height of a randomly chosen college student, amount of electricity used to light a randomly chose classroom)

Question 4

probability distribution

Answer 4

for a discrete random variable, specifies the probability for each possible value of the random variable (must add up to 1)

Question 5

mean of a random variable

Answer 5

provides a measure of center for the probability distribution of a random variable

Question 6

mean on the TI-84 plus

Answer 6

1) enter the values of the random variable into L1 and the associated probabilities in L2. 2) press STAT and highlight the CALC menu and select 1-Var stats and enter L1, comma, L2 and run the command

Question 7

Expected value

Answer 7

used to predict how much they are likely to gain or lose from a decision. Often done by computing the mean of a random variable, deeming its name expected value or E(X)

Question 8

Variance and standard deviation measure spread

Answer 8

of a random variable, measure the spread in a probability distribution

Question 9

Finding mean and standard deviation in calc that has stat wizards

Answer 9

1) put data in L1 and L2. 2)stats command and 1-vars, L1 in list and L2 in the frequency list