Introduction to Probability and Statistics

AP Stats Intro to Probability

​The Law of Large Numbers

This law says that, in the long run, as we repeat a random process over and over, the proportion (or percentage) of times that an event occurs gets closer and clsoer to one number. We call that number the Probability of an event.

​Probability of an Event

​P(event A) = # of outcomes in event A/total # of possible outcomes

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​P(event A) = # of times event A occurs/total # of trials

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Multiple Choice

P(impossible event)

• 1

• 0

• 0.5

• 0.9

Multiple Choice

P(certain event)

• 0

• 1

• 0.2

• 0.33

Multiple Choice

True or False: Probability can be greater than 1.

• True

• False

Open Ended

Find the probability that each event occurs: P(coin flip lands on heads)

Open Ended

Find the probability: P(roll a 3 on a die)

Open Ended

Find the probability: P(face card)

Open Ended

Sample space is a collection of all possible outcomes. Find the sample space for the end of rolling an odd number on a die.

Open Ended

Find the sample space of P(land on 10 rolling 2 dice)

Open Ended

Find the sample space of P(pull a spade from a card deck)

Open Ended

Complement: The probability of something NOT occuring. If the probability of you getting to class on time is 0.85, what's the probability that you don't get to class on time?

Open Ended

You have 6 marbles: 2 red, 3 green, 1 blue, and 2 yellow. What is the sample space for picking a marble from the bag?

Open Ended

You have 6 marbles: 2 red, 3 green, 1 blue, and 2 yellow. Find P(red).

Open Ended

You have 6 marbles: 2 red, 3 green, 1 blue, and 2 yellow. Find P(not blue).

Open Ended

Jerry has a 75% chance of catching a red light and 23% chance of catching a green light on his way home from work today. What's the probability that Jerry doesn't catch a green light?

Open Ended

Jerry has a 75% chance of catching a red light and 23% chance of catching a green light on his way home from work today. What's the sample soace for this event?

Open Ended

Jerry has a 75% chance of catching a red light and 23% chance of catching a green light on his way home from work today. What's the likelihood that Jerry catches a yellow light on his way home today?

Poll

How do we feel about this intro to probability?

• Confident! I'm ready to move on to the next piece on probability.

• I'm ready to move on but would like to continue to practice these foundational skills.

• I am almost ready to move on. Need one more day of basic practice.

• I am not ready to move on. I need to relearn this.