AP Statistics Chapter 4 Test

Question 1

population

Answer 1

the entire group of individuals we want info about

Question 2

census

Answer 2

collects data from every individual in the pop.

Question 3

sample

Answer 3

subset of individuals in the pop. from which we actually collect data

Question 4

sample survey

Answer 4

study that collects data from a sample that is chosen to represent a specific pop.

Question 5

convenience sample

Answer 5

choosing individuals from the pop. who are easy to reach; often produces unrepresentative data

Question 6

voluntary response sampling; volunteers tend to have ____

Answer 6

allows people to choose to be in the sample by responding to a general invitation; strong opinions and are not representative of pop.

Question 7

random sampling

Answer 7

chance process to determine which members of a pop. are included in a sample

Question 8

simple random sampling

Answer 8

every individual in a chosen pop. has a chance of being selected

Question 9

N

Answer 9

number of individuals in a pop

Question 10

n

Answer 10

number of individuals in a sample size

Question 11

strata

Answer 11

groups of individuals in a pop. who share characteristics thought to be associated with the variables being measured in a study

Question 12

stratified random sampling

Answer 12

choosing an simple random sample from each stratum and combining the SRSs into one overall sample

Question 13

cluster

Answer 13

group of individuals in pop that are located near the other

Question 14

cluster sampling

Answer 14

randomly choose clusters and including each member of the selected clusters in the sample

Question 15

systematic random sampling

Answer 15

ordered arrangement of pop; randomly selects one for the first k individuals and choose every kth individual thereafter

Question 16

undercoverage

Answer 16

some members of the pop. are less likely or cannot be chosen in a sample

Question 17

nonresponse

Answer 17

when an individual chosen for the sample can’t be contacted or refuses to participate

Question 18

response bias

Answer 18

occurs when there is a systematic pattern of inaccurate answers to a survey question

Question 19

observational study

Answer 19

observes individuals & measures variables of interest without influencing the responses

Question 20

response variable

Answer 20

measures an outcome of a study

Question 21

explanatory variable

Answer 21

helps explain or predict changes in response variable

Question 22

confounding variable

Answer 22

two variables are associated in such a way that their effects on the response variable is indistinguishable

Question 23

Experiment

Answer 23

deliberately impose some treatment on individuals to measure their responses

Question 24

placebo

Answer 24

treatment with no active ingredient, but is otherwise like other treatments

Question 25

Experimental unit

Answer 25

object to which a treatment is randomly assigned(e.g.: humans)

Question 26

treatment

Answer 26

specific condition applied to the individuals in an experiment

Question 27

factor

Answer 27

variable that is manipulated and may cause a change in the response variable

Question 28

levels

Answer 28

different values of a factor

Question 29

control group

Answer 29

used to provide a baseline for comparing the effects of other treatments; should be treated exactly the same as other treatment groups

Question 30

placebo effect

Answer 30

some subjects in the experiment will respond favorably to any treatment, inactive or not

Question 31

double-blind experiment

Answer 31

BOTH the subjects and experimenters don't know which subjects are receiving the treatment

Question 32

random assignment

Answer 32

Experimental units are assigned to treatments using a chance process

Question 33

control

Answer 33

keeping other variables constant for all experimental units

Question 34

replication

Answer 34

using enough experimental units to distinguish a difference in the effects of the treatments from chance variation due to the random assignment

Question 35

completely randomized design

Answer 35

the experimental units are assigned to the treatments by chance

Question 36

block

Answer 36

group of experimental units that are known before the experiment to be similar in some way that is expected to affect the response to the treatments

Question 37

randomized block design

Answer 37

the random assignment of experimental units to treatments is carried out separately within each block

Question 38

matched pairs design(1); two very...

Answer 38

two very similar designs are paired and the two treatments are randomly assigned within each pair

Question 39

matched pairs design(2); each...

Answer 39

each experimental unit receives both treatments in random order

Question 40

sampling variability

Answer 40

refers to the fact that different random samples of the sample size from the same population produce different estimates

Question 41

the larger the sample size, _______ and _______.

Answer 41

less variability; higher precision