Probability Distributions

Question 1

What 3 requirements must every probability distribution satisfy?

Answer 1

1. There is a numerical random variable x and its values are associated with corresponding probabilities.
2. EP(x)= 1 where x assumes all possible values.
3. 0 = 1 for every individual value of the random variable x. (That is, each probability must be between 0 and 1 inclusive.)

Question 2

random variable

Answer 2

A variable (typically represented by x) that has a single numerical value, determined by chance, for each outcome of a procedure.

Question 3

probability distribution

Answer 3

A description that gives the probability for each value of the random variable. It’s often expressed in the format of a table, formula, or graph.

Question 4

What does the vertical scale show on a probability histogram?

Answer 4

Probabilities.

Question 5

What 4 requirements must results from a procedure meet to be considered a binomial probability distribution?

Answer 5

1. The procedure has a fixed number of trials. (trial= single observation)
2. The trials must be independent. (The outcome of any individual trial doesn’t affect the probabilities in the other trials.)
3. Each trial must have all outcomes classified into two categories (commonly referred to as success and failure.)
4. The probability of success remains the same in all trials.