Do Now 5/18 How many license plates are in both group V and group E? Essential Question: How can you determine if 2 events are independent?

Agenda Do Now Good Things! Recap: Independent vs Dependent Frequency Tables Notes: Proving independence from frequency tables

GOOD THINGS

Lesson Intro P(A and B) = P(A) • P(B) Law of Large Numbers More data = more reliable results Independent – not influenced by other events Key words: “with replacement” Dependent – the first event before changes what happens in the future Also called “conditional” probability Key words: “without replacement” or “given that” Independent Dependent P(A and B) = P(A) • P(B)

Determine the Probability What is the probability that 2 cards selected from a standard deck of 52 cards without replacement are both red? What is the probability that 2 cards selected from a standard deck of 52 cards without replacement are both non-face cards?

Frequency Tables The VERY FIRST THING you should do when you see a frequency table is to find the totals – every time. Total for each column Total for each row Total of entire table

Frequency Tables Which probability is the greatest? A. The probability that a student went to Red River given that the student is a pre-law major B. The probability that a student went to South Lake given that the student is a marine science major C. The probability that a student is a marine science major given that the student went to Red River D. the probability that a student went to South Lake A

Independent Events What does this mean????? Events A and B are independent events if: What does this mean????? The probability of one event happening given that another event happened is the exact same as if the other one never happened!!

Independent Events Let’s say that Event A is “having pasta for dinner”, and Event B is “Thursday.” If the probability of having pasta for dinner is the same regardless of what day it is, then it is INDEPENDENT of Event B, “Thursday.”

Independent Events Grade Activity choice Total Talent show Field trip Dance 10 4 8 2 14 11 5 3 6 12 1 9 17 40 This is the same chart as yesterday, so if you have it in your notes flip to it

Frequency Tables and Independent Events Events A and B are independent events if: Let’s see if being a 11th grader is independent from voting for a field trip. A = field trip B = 11th grade P(Field Trip| 11th grade)? P(Field Trip)? Same result if you do it backwards as well P(11th grade |Field Trip)? P(11th grade)?

Frequency Tables and Independent Events

Practice Problems! ~25 minutes We will review the work together at the end! http://www.problem-attic.com/test/ljhddwqv