1. WARMUP Lesson 10.3, For use with pages 698-704
Write the number as a percent.
ANSWER 3% 25 1 2.
ANSWER
140% 58 3.
ANSWER
62.5%
ANSWER
0.45% 5.
Two-thirds of the senior class work more than 20 hours per week. Write that fraction to the nearest tenth of a percent.
ANSWER
66.7% 6.
RailRoad cRossing look out for caRs. How do you spell that without any R’s?

2. Gameshow Problem The scenario is such: you are given the opportunity to select one closed door of three, behind one of which there is a prize. The other two doors hide “goats” (or some other such “non-prize”), or nothing at all. Once you have made your selection, The Host will open one of the remaining doors, revealing that it does not contain the prize 2. He then asks you if you would like to switch your selection to the other unopened door, or stay with your original choice. Do you switch? Does it matter?

3. The Monty Hall Problem https://www.youtube.com/watch?v=mhlc7peGlGg

5. https://www.youtube.com/watch?v=WKR6dNDvHYQ The other way

6. 10.3 Notes - Define and Use Probability
Craps Tutorial
Roulette Simulator

7. Probability = Happiness over Everything

8. Objective -To find theoretical, experimental and
geometric probabilities.
P(3)=
P(factors of 8)= 1 2 3 4 5 6 7 8
P(prime #)=
P(9)=

9. Probability Probability of Success: Probability of Failure:
s = # of ways to Succeed
f = # of ways to Fail
Probabilities MUST be between 1 & 0

10. Four cards are drawn from a standard 52-card deck. What
is the probability that the first three cards are black?
Five cards are drawn from a standard 52-card deck. What
is the probability that the first five cards are spades?

11. Find the probability of throwing a dart and hitting the
shaded region if you hit the square.
Area of a Circle
A = r2
A = (4)2
4 cm.
Area of Shaded
A = 82 - (4)2
Area of a Square
A = (side)2
A = (8)2
P(Sh.Reg) =

12. 6 cm. Find the probability of throwing a dart and hitting the
shaded region if you hit the rectangle.
Remember your Triangles:
Area of  =
½  base  ht
Area of  =
base  ht 3
6 cm.
P(Sh.Reg) =

13. Given: a Box of 5 BLUE pencils & 4 RED Pencils
Given: a Box of 5 BLUE pencils & 4 RED Pencils. If a Pencil is chosen at random, what is the P(Blue)?
2. 6 Men and 3 Women: If 2 people are chosen at random, What is P(Both Women)?
B B B B B R R R R
M M M M M M
W W W

14. Odds vs Probability
If Probability =
, then ODDS =

15. Odds are Happiness vs Sadness

16. OR 1:5 1. What are the ODDS of rolling a 3 on a six sided die?
Card Deck: Draw 5 Cards. What are the ODDS the 1st 4 cards drawn will be HEARTS and the 5th card a SPADE?
OR 1:5

17. EXAMPLE 1
Find probabilities of events
You roll a standard six-sided die. Find the probability of (a) rolling a 5 and (b) rolling an even number.
SOLUTION
There are 6 possible outcomes. Only 1 outcome corresponds to rolling a 5.
Number of ways to roll the die
P(rolling a 5) =
Number of ways to roll a 5 = 1 6

18. EXAMPLE 1
Find probabilities of events
A total of 3 outcomes correspond to rolling an even number: a 2, 4, or 6.
P(rolling even number) =
Number of ways to roll an even number
Number of ways to roll the die = 3 6 1 2 =

19. EXAMPLE 2
Use permutations or combinations
Entertainment
A community center hosts a talent contest for local musicians. On a given evening, 7 musicians are scheduled to perform. The order in which the musicians perform is randomly selected during the show.
What is the probability that the musicians perform in alphabetical order by their last names? (Assume that no two musicians have the same last name.)

20. EXAMPLE 2
Use permutations or combinations
SOLUTION
There are 7! different permutations of the 7 musicians. Of these, only 1 is in alphabetical order by last name. So, the probability is:
P(alphabetical order) = 1 7! 1
5040 = ≈

21. EXAMPLE 2
Use permutations or combinations
There are 7C2 different combinations of 2 musicians. Of these, 4C2 are 2 of your friends. So, the probability is:
P(first 2 performers are your friends) =
4C2
7C2 6 21 = 2 7 =
0.286

22. GUIDED PRACTICE
for Examples 1 and 2
You have an equally likely chance of choosing any integer from 1 through 20. Find the probability of the given event.
A perfect square is chosen. = 1 5
ANSWER

23. GUIDED PRACTICE
for Examples 1 and 2
You have an equally likely chance of choosing any integer from 1 through 20. Find the probability of the given event.
A factor of 30 is chosen. = 7 20
ANSWER

24. GUIDED PRACTICE
for Examples 1 and 2
What If? In Example 2, how do your answers to parts (a) and (b) change if there are 9 musicians scheduled to perform?
The probability would decrease to
ANSWER 1
362,880
The probability would decrease to 1 6

25. EXAMPLE 3
Find odds
A card is drawn from a standard deck of 52 cards. Find (a) the odds in favor of drawing a 10 and (b) the odds against drawing a club.
SOLUTION
Odds in favor of drawing a 10
Number of non-tens =
Number of tens = 4 48 = 1 12
, or 1:12

26. EXAMPLE 3
Find odds
Odds against drawing a club
Number of clubs =
Number of non-clubs = 39 13 = 3 1
, or 3:1

27. EXAMPLE 4
Find an experimental probability
Survey
The bar graph shows how old adults in a survey would choose to be if they could choose any age. Find the experimental probability that a randomly selected adult would prefer to be at least 40 years old.

28. EXAMPLE 4
Find an experimental probability
SOLUTION
The total number of people surveyed is:
= 3516
Of those surveyed, = 1089 would prefer to be at least 40.
1089
3516
P(at least 40 years old) =
0.310

29. GUIDED PRACTICE
for Examples 3 and 4
A card is randomly drawn from a standard deck. Find the indicated odds.
In favor of drawing a heart
ANSWER 1 3

30. GUIDED PRACTICE
for Examples 3 and 4
A card is randomly drawn from a standard deck. Find the indicated odds.
Against drawing a queen
ANSWER 12 1

31. GUIDED PRACTICE
for Examples 3 and 4
What If? In Example 4, what is the experimental probability that an adult would prefer to be (a) at most 39 years old and (b) at least 30 years old?
ANSWER
a. about 0.69
b. about 0.56

32. EXAMPLE 5
Find a geometric probability
Darts
You throw a dart at the square board shown. Your dart is equally likely to hit any point inside the board. Are you more likely to get 10 points or 0 points?
SOLUTION
P(10 Points) =
Area of entire board
Area of smallest circle
182 π =
324 9π 36 π
0.0873

33. EXAMPLE 5
Find a geometric probability
Area of entire board
P(0 points) =
Area outside largest circle
182
182 – (π ) = =
324
324 – 81π = 4
4 – π
0.215
ANSWER
Because > , you are more likely to get 0 points.

34. GUIDED PRACTICE
for Example 5
What If? In Example 5, are you more likely to get 5 points or 0 points?
ANSWER
Because > 0.215, you are more likely to get 5 points.

35. EXAMPLE 5
Find a geometric probability
Area of entire board
P(0 points) =
Area outside largest circle
182
182 – (π ) = =
324
324 – 81π = 4
4 – π
0.215
ANSWER
Because > 0.215, you are more likely to get 5 points.

36. 10.3 Assignment
10.3: ODD, 50(3), 51(1), 52(2), 53(9), 58(56), 60(35)
Numbers in parenthesis are the answers to those problems. You still need to show work are log problems. Look in the solution manual or Chapter 7 in the book for help.
Experimental probability is data given in a chart from an experiment that ACTUALLY happened.
Theoretical probability is what we’ve been doing where we calculate what SHOULD happen.