Unit 5 WS 3 Prob and Stats Concepts – sampling and random # PRACTICE
1. Explain why we use samples instead of the population.
2. Mrs. Thompson has three classes she co-teaches. She wants to survey a small sample of her students
about how prepared they felt for the ACT. Describe how she could pick this sample using each of the 6
methods. Make the direction clear enough that an outsider could see what you wrote and now exactly
what to do.
a. Random
b. Systematic
c. Stratified
d. Cluster
e. Convenience
f. Voluntary
3. Someone on the Town Council wants to know what Mt. Pleasant residents think about the traffic. She
posts signs around Mount Pleasant that give a website people can visit to fill out the survey. What type
of sampling is this? Describe why this might create a sample that is NOT representative of the
population.
State the type of sampling used (random, systematic, stratified, cluster, convenience, voluntary)
4. A researcher gets a list of all of the streets in Mount Pleasant. He randomly picks 4 of them and visits
every house on those 4 streets.
5. A researcher gets the names of every housing development in Mount Pleasant. He picks two
residents of each to be in a study.
6. A teacher gets a lists of all of her students and numbers them 1-92. She then uses a random number
table to pick a sample of 12 students.
7. At an elementary school recess every student is lined up. The principal goes down the line and picks
every 10th student to be in a sample.
8. At an elementary school, all of the students eat lunch in the cafeteria at the same time. The Principal
goes to the lunch room and randomly selects three of the cafeteria tables. Every student from those
tables are surveyed.
9. At an all school pep rally – the students are seated by grade level. Twenty students from each grade
are chosen to be part of a survey.
10. A pollster writes a facebook post that includes a link for people to take an online survey.
11. A teacher separates her students by their class grade (A, B, C, D, or F). Two students from each
group are chosen.
12. A computer randomly dials numbers from the Mount Pleasant Phone book.
13. A dentist is trying to find out the satisfaction level of his patients. He has his secretary print a list of
every patient. He then selects every 5th person on the list to receive a survey.
14. A WHS administer wants to know students opinion on parking at Wando. He randomly selects 5
parking rows and polls every student who parked in those 3 rows.
15. A WHS administer wants to know students opinions about lockers. She walks down the hall and
stops several students to answer the questions.
16. The landlord of an apartment building gets the names of every tenant in his buildings. He separates
them into male and female and picks five people from each group to survey.
17. A hotel manager of a 15 story hotel randomly picks one floor to check all of the rooms for cleanliness
and judge the quality of the maid service.
18. Do you think the sampling method used in #17 was a good method? Why or why not? If no – what
other method would be better?
Find the random sample that would be generated.
19. You have a list of 50 people. Use the random number list to pick 10 of them to be in a sample.
People picked:
20. You have a list of 700 people. Use the random number list to pick 20 of them to be in a sample.
People picked:
21. You have a list of 75 people. Use the random number list to pick 10 of them.
People picked:
22. You are considering moving to a certain city. You want to see what the restaurant options are like.
You get a list of all of the places to eat in that city and decide to visit 10 of them. Use the random
number list to pick the 10 restaurants and circle the ones you picked.
(number the restaurants by going DOWN first)
Mcdonalds
Burger King
Subway
Pizza Hut
Papa Johns
Outback
PF changes
Wendys
Chipotle
Moes
Olive Garden
Panera
Red Lobster
Red Robin
TGI Fridays
Sonic
Canes
Chick Fil A
Applebees
Taco Bell
Jersey Mikes
Atlanta Bread
Quiznos
Dominos
Qudoba
23. A teacher wants to make a committee of 10 of her students. Below are a list of all of her students.
Use the random number list to pick the 10 students. Start by numbering down and circle the picked
students.
Alex
Erin
Justice
Devin
Katie
Tony
Sara
Ellen
Walker
Graham
Marissa
Zach
Megan
Margo
Cameron
Jeff
Mary
Will
Michael
Laura
John
Charlotte
Kelly
Jane
Sydney
A restaurant reviewer wishes to check out the cuisine in the Lansdale area. His population
is 72 restaurants that are Chinese (C), Italian (I), and Mexican (M). The list is
alphabetically as follows.
a. Analyze how many of each type of restaurant there are in this area. (the % will be out of 72)
Total Chinese:___________
Total Italian:_____________
Total Mexican:___________
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Abacus
Allegro
Bacco
Baja Fresh
Boston Style
Brother's
China Garden
China Moon
China Wok
Chinese Kitchen
Chong's
Chuck E Cheese
Cosimo's
Country Garden
Domino's
Domi’s
Eastern Dragon
El Cactus
C
I
I
M
I
I
C
C
C
C
C
I
I
C
I
I
C
M
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
Percentage of Chinese:____________
Percentage of Italian: ____________
Percentage of Mexican:__________
El Sarape
Fasageos
Frank's
Fratellis
Georgina's
Giuseppe's
Golden Chopsticks
Golden City
Golden Sea
Gourmet Wok
Great Wall
Habaneros
Hong Kong Chef
Hunan Best
Imperial Palace
Italia
Italian Delite
Kowloon
M
I
I
I
M
I
C
C
C
C
C
M
C
C
C
I
I
C
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Laura's
Lisa's
Los Tacos
Lotus Inn
Luca's
Lu's
Macaroni Grille
Mama's
Mexican Grille
New Station
Nino’s
Palermo's
Panda Garden
Papa John's
Pizza Hut
Pizza Plaza
Pizza Time
Portofino
I
I
M
C
I
C
I
I
M
I
I
I
C
I
I
I
I
I
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
Ray's
Rising Sun
Sbarro's
Soncini's
Sophie's
Spatola's
Star Buffet
Sushi Express
Taco Bell
Tacqueria
Tamarindos
Tex Mex
Tortillas
Uno
Via Marconi
Vinny's
Wok and Roll
Yantze
b. Use the following random # list to pick out 12 restaurants the reviewer is going to visit. Circle the 12
above.
c. Analyze your sample of 12. (% will be out of 12)
# of Chinese in the sample:__________________ percent:_________________
# of Italian in the sample:____________________ percent:_________________
# of Mexican in the sample:__________________ Percent:_________________
d. Do you think that this sample of 12 is representative of the restaurants? Explain If no – what method
of sampling may have been better?
I
C
I
I
I
I
C
C
M
M
M
M
M
I
I
I
C
C