Geometry Support Unit • 7—Probability Notes

Name Date

Day 4—Frequency Tables

****To find the probability using a table, you will take the

total from whatever category it's asking for divided by

the OVERALL TOTAL.

I. Using the table to the right, find the probability

that a person is wearing yellow (take the total of the

people wearing yellow divided by the overall total).

bL2. find the probability of not having blue eyes.

bL3. Find P(not wearing yellow).

4. In the table to the right, write the totals of each row

and column and the overall total (just like it looks in

the table from problem I You will do this for the rest

of the problems on this paper too!!

5. find P (female)•

6. Find P(not owning a pet)

7. find P(wash the dishes)

8. Find P(male)

9. Find the probability that a sample of a pieceof waste was made out of plastic

10. Find the probability that piece of waste wasmade out of metal or glass

Blue Eyes

Not Blue Eyes

Totals

Wearing Yellow

10

30

40

Not WearingYellow

2

20

22

Do you own a pet?Female

Male

Did you wash thedishes last night?

Female

Male

Yes8

5

13

Yes

7

7

MaterialPaper

Metal

GlassPlastic

Other

Recycled 34.9

6.5

2.9

1.1

15.3

Not Recycle48.9

10.19.1

20.4

67.8

NotesGeometry Unit 7—Probabüity

Name Date

Day 5—Conditional Probability

thesanpkspaceforateveN.

ertdMUs••• Youcanwiteaconditionalprobabütyusingthenotation:

A Is nu» P( I )=P(B given A)

gNtnl. The table shows the results of a class survey.

a. Of the males. how rnany don't own a pet?

1i. Write the above statement as a $ven

statement.

b. Find P(ownapet I female).

2 The table shows the results of a class survey.

a. Look below at questions b and c. What is thedifference between the two statements?

b. Find P(wash the dishes I male)

15

c. Find P(rnale I wash the dishes)

3. Using the data in the table:

a. Find the probability that a sample ofnot recycled waste was plastic.

LOA

b. P(recydedl paper)

34.4

Do you own a pet? Yes

Female 8

Maie

13

Did you wash theYesdishes last night?

Female 7Male 7

No

No

6 8

MaterialPaper

Recycled34.9

Not Recycled48.9

1316

Y3.!MetalGlassPlasticOther

6.5

2.9

1.1

15.3

10.1

9.1

20.4

67.8

156.3

Geometry Support Unit 7—Probability Notes4. Carter surveys students in hisschool who play sports. and asksthem which sport they prefer. Herecords the responses in the table.

GenderBaseball

Male 49

Female 23

Preferred rtSoccer

52

64

Basketball

16

33

• Find the probability that arandomly selected female studentprefers baseball.

110

• find P(male I soccer)

• Find P(basketball I male)

111

5. A faculty advisor at Ridge High School surveyed 100 students about their preference for a social

event. Of the 100 students surveyed, 50 were tenth graders and 50 were eleventh graders. Of the

tenth graders, 30 chose a bowfing party and 20 chose a dance. Of the eleventh graders, 20 ch0N

bowfing party and 30 chose a dance.

l. Make a two way frequency table to represent the data.

Bowling (B) Dance (D)

1 0th graders (T)10

I I th graders (E) 50

60 60

2. Find P(B). 50

IDO

3. Find P(BIT). 30

s 50

3eometry Support Unit 7—Probability Notes

Felipe surveyed students at his school about whether or not they owned a cell phone or an MP3

)layer. but he lost some of the numbers. Help him fill in the rest of his chart.

MP3 PEF L_yoW3 Player Total

57 78

No 13 t),1.4

10 3D

a) Find P(cell phone)

b) Find P(no MP3 player)3D

IDD

c) Find P(No cell phone I MP3 player)13

d) Find P(no MP3 player I no cell phone)

7. The chart below shows students' hair color and eye color combinations. Fill in the missing spaces.

Hair Calor

Black Brown Red Blond Total

12 2321

Tmal I 13

a) find P (brown hair)

b) Find P(hazel eyes I blond hair)

c) Find P(green eyes)

d) Find P(red hair I blue eyes)

Geometry Support Unit 7—ProbabilityUsinq the Formula

• The formula f conditional probability is:

Notes

l. Researchers asked people who exercise regularly whethe eyjog or walk.Fifty-eight cent of the respondents were mal Twenty ercent of all respondents werema who said they jog. Find the probability that a randomly selected person jogs given theyare male.

.58

2. In Euro 88% all households have a televisio 51% f all households have a television and anX-Box. What is e probabifity that a household has a X-Box given that it has a television?

.51 .58 58 •l.

3. A bag contains blue and yellow marbles. Two marbles are drawn without replacement. Theprobability of selecting a blue marble and then a yellow marble i .37 nd the probability of selectinga yellow marble on the second draw, if the first marble drawn was blue i .67. hat is the probabilityof selecting a blue marble?

31 .31 —i .65

551.

? probabili

4. The probability that Sue will go to Mexico in the winter and to France in the summer is 0.40 Theprobability that she will o to France this summer, given that she just returned from her Win ervacation in Mexico i .61. Find the probability that she will go to Mexico

pY0b(bi

1,

NotesGeometry Support

The frequencies of the

Unit 7---Probabüity

Day 5 Homework

a bag are shown the table.

find P(smaU) GREEN BLUE

8 12

A town piamhg commütee is considerütg a new system for public transi. Residentshe town were randomty selected to answer two questions: "Do you work less than 5mies from hdme?" arid "Would you use the new system to get to work. wereavailable? • The resuts are shown the table below.

b 3. If residents work less than 5miles from home. what is the

that they woulduse the new system?

Use newsystem?

4- If residents wiling to usethe new system. what is theprobabiity that they don't workless than 5 mules from home?

Work less than 5mNes from home?

YES NO

24 32

20

The t±le shows the resurs of a pou of randomly selected high school students whowere asked they prefer to hear an school announcements in the mornhlg or

5. Find P(Moming -l Underclassmen)

6. FindUnderclassmen Upperclassmen

8 14

18 10

P(Aftemoon I Upperclassrnen)

The table shows the resuås of a customer survey for a cenular serviceprovider. by location the customer. In the survey. customers were asked whetherthe would recommend a plan with the provider to a friend.

0 7. Find P(Yes)Arlington Towson Parkville

8. Find (Yes I Arlington) Yes 40 35 4118 10.

56

SD

11b

9. Are the 2 probabilities the150

same?

.11160

Geometry Support Unit 7-—Probability Notes

Roberto is the owner of a car dealership. He is assessing the success rates of his topthree sales people in order to offer one of them a promotion. Over two months, foreach attempted sale, he records whether the sales person made a successful sale ornot. The results are shown in the cart below.

b //IZ 10. Find P(Successful I Becky)

q 15 11. Find P(Unsuccessful I Darrell)

Successful UnsuccessfulBec 6 6

Raul 4 5

Darrell 6 9 15

1b 3bMrs. Koehler surveyed 430 men and 200 women about their vehicles. Of those surveyed,160 men and 85 women said they own a blue vehicle.

12. If a randomlychosen person is aman, what is theprobability of that

BlueMen

Women

person having a blue car? 1.1..15

Not Blue830zoo

335 b3D

Use the formula:

13. The probability that it is Friday and that a student is enti 0.03 ince there are 5school days in a week, the probability that it is Friday 0.2. ha IS he probability that astudent is absent given that today is Friday?

.03 - .15

14. In Georgia, the probability that a house has a gar ei 84% The probability that ahouse has a backyard given that it has a garage i 7% Wh s the probability that ahouse has a garage and a backyard?

house and

• 77 _

bb•l.