Lesson 17 – Do Now

Do now Expectations:No talking for any reason, please.

1) Find the solution:

2) Find the GCF of 36 and 42

3) Solve for the indicated variable

SWBAT determine the probability of the complement of an event occurring.

Key Skills: • Sample Space• Simplifying Fractions• Subtraction/Addition

There are 8 questions on the benchmark that use this skill.

Lesson 17

Today’s Big Question(s):

How is finding the complement of a probability problem important when solving for probability?

Lesson 17

Vocabulary:

Complement

The complement of an event is all the outcomes in the sample space that are not included in the event.

P(event) + P(complement of event) = 1

Two events are complementary events if the sum of their probabilities equals 1 and if one event occurs if and only if the other does not.

DI - Lesson 17

DI - Lesson 17

1) The weather forecast predicts a 20% chance of snow. What is the probability that it will not snow?

2) If the probability of an event is 3/8, what is the probability of its complement?

DI - Lesson 17

DI - Lesson 17 3) A fair die is thrown. What is the probability that

the score is not a factor of 6?

DI - Lesson 17 4) A pair of dice are rolled.  What is the probability

of not rolling doubles?

5). A gumball machine contains gumballs of five different colors:  36 red, 44 white, 15 blue, 20 green, and 5 orange.  The machine dispenser randomly selects one gumball.  What is the probability that the gumball selected is:a.) green?b.) not green?c.) not orange?d.) orange?e.) not a color in the flag of the USA?f.) red, white, or blue?

You have ___________ minutes to silently/independently complete the guided practice problems on your handout.

I will walk around and give you feedback on your work.

GP – Lesson 17

EXAMPLE: A pair of dice are rolled.  What is the probability of rolling 10 or less?

GP - Lesson 17

EXAMPLE: We are going to shuffle a deck of playing cards. Let’s suppose we are going to draw one card from this deck. Can you find the probability that the card is not a king?

GP - Lesson 17

EXAMPLE: Find the probability that the card is not a club.

GP - Lesson 17

EXAMPLE: A pair of dice will be rolled. Find the probability that at least one of the two rolls is an odd number.

GP - Lesson 17

EXAMPLE: According to the American Veterinary Medical Association, 31.6% of American households own a dog. What is the probability that a randomly selected household does not own a dog?

EXTRA Credit/Merit OPPORTUNITY!!!!

THIS THURSDAY, FEB. 20

After school, Room 413

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ClosingMastery Check

Answer the following questions in your notes.

What are the three ways that one can represent the probability of an event occurring?