Theoretical Probability Expected Events

What is probability?

• the set of all possible outcomes for an event

• the outcome where the second event does not depend on the first event

• an event that is certain to happen

• the chance that an event will occur and is expressed as a ratio with the favorable outcomes to (over) the number of total possibilities

An event that has a probability of zero is _____________.

• equal

• certain

• dependent

• impossible

Mr. Adamson will toss a fair coin 3 times. The possible results are illustrated in the tree diagram below. Based on the information given in the tree diagram, what is the probability that Adamson will toss two or more tails?

Ms. Thompson tossed a fair coin 6 times and got heads every time. Theoretically, what will happen on the next toss of this coin?

• She will definitely toss tails.

• She will definitely toss heads.

• She is neither likely nor unlikely to toss a head.

• She is more likely to toss heads than tails.

Each of the six faces of a certain cube is labeled either X or Y. When the cube is tossed, the probability of the cube landing with side X face up is ⅔ . How many faces are labeled X?

• 2 Faces

• 3 Faces

• 4 Faces

• 6 Faces

An experimental probability may not match its theoretical probability. Which number of trials will most likely give an experimental probability that will most closely match the theoretical probability of the event?

• 1 event

• 5 events

• 15 events

• 25 events

Ms. Phillips rolls a number cube with faces numbered 1 to 6 is rolled 24 times. In theory, how many times would she expect to roll a number greater than 4?

• 10

• 8

• 20

• 12

Mrs. Key rolls two fair number cubes. Using the number sum chart, find the probability that he will roll values on the number cubes that have a sum of four. Write the answer in simplest form.

• 0

A coin is tossed and a fair number cube is rolled.

Find the P(heads and 2 or 3).

The quality control engineer for a gaming system found that 9 out of every 60 gaming systems were defective.

On Tuesday they tested 400 devices. They found that only 4 gaming systems were defective. Based on the theoretical probability, how many gaming systems would you have expected to be defective?

• 9

• 90

• 60

• 400