# What Are Probabilities?

Warmup

Activity #1

Discover Probability Sample Space.

The probability of getting a certain sum is the number of all possible combinations on the two dice that add up to the number. • Select a question and click on all pairs that satisfy the problem.

Activity #2

Graphing a probability. • Throw a die 36 times and write down all the events that occur.
• Enter the number of times you rolled each sum below the corresponding sum. Your graph will display this data, and the probabilities of rolling each sum will appear below.
• Make sure that the probabilities have a denominator of 36!

(1.) Based on the experimental probabilities, what sum are you most likely to roll? Least likely? Did this surprise you? Why or why not?

(2.) Do you notice anything special about the general shape of the graph? Explain why this might be.

(3.) Based only on this data, if you had to guess what sum you would roll next, what would you choose and why?

Challenge #1

List the sample space for the following experiments:

(1.) Selecting a random season of the year

(2.) Selecting a random day of the week.

(3.) Flipping a coin and throwing a die.

Challenge #2

A computer randomly selects a letter from the alphabet.

(1.) How many different outcomes are in the sample space?

(2.) What is the probability the computer produces the first letter of your first name?

(3.) What is the probability of selecting a random month of the year and getting a month that starts with the letter “J?” If you get stuck, consider listing the sample space.

Quiz Time