Test

Question 1

Categorical

Answer 1

Most common: graphical display
Pie chart
Bar chart

Pictograms
Frequency tables

Numerical summaries: category counts and percentages

Question 2

Quantatative

Answer 2

Histogram [=including, (=not including
Stem plot
Box plot (5# summary)
- longer/shorter quartile means spread of data not more data

Question 3

Mean

Answer 3

Average

Question 4

Median

Answer 4

Middle

Question 5

More

Answer 5

Most often occurring

Question 6

Standard Deviation

Answer 6

Use w/ symmetry and mean

68% fall w/in 1 SD of the mean
95% fall w/in 2 SD of the mean
99% fall w/in 3 SD of the mean

Question 7

IQR

Answer 7

Inner quartile range

Gives us the middle 50%

Used w/skewed data and median

Question 8

1.5 IQR

Used to detect outliers

Answer 8

Q1-1.5(IQR)

Q3-1.5(IQR)

Question 9

Explanatory Variable

X

Answer 9

Variable that claims to explain, predict or affect the response

Question 10

Response variable (Y)

Answer 10

Outcome of the study

Question 11

C — Q

Answer 11

Box plots

Question 12

C — C

Answer 12

Two way tables / contingency table

Question 13

Q — C

Answer 13

Conditional percentile tables

Question 14

Q — Q

Answer 14

Scatter plot

Increase in X = increase in Y
Decrease in X = decrease in Y

U shape = not positive or negative

Question 15

r= linear correlation coefficient

Answer 15

( -1 to 1 )

0 to -1 = neg relationship
0 to +1 = pos relationship

Measures strength of linear relationship

Question 16

Simpsons Paradox

Answer 16

When a lurking variable causes us to think the direction of an association

Question 17

Population

Answer 17

Group chosen for sampling

Question 18

Sample Frame

Answer 18

List of individuals to be sampled

Question 19

Sample

Answer 19

Actual individuals chosen for sample

Question 20

Simple Random Sample

Answer 20

Individuals sampled at random without replacement.

Selecting names out of a hat

Question 21

Cluster sample

Answer 21

Used when population is naturally divided into groups

Students in university divided into majors

Question 22

Stratified sample

Answer 22

Used when population naturally divided into subpopulations

Students in certain college divided by gender or year in college

Question 23

Systematic sample

Answer 23

Obtain contact information and sample every so many people (I.e. Every 50th person)

Question 24

Observational Study

Answer 24

Values of variables are recorded as they naturally occur

Question 25

Experiment

Answer 25

Researcher defines the explanatory variable

Question 26

Prospective

Answer 26

Values of the variables recorded forward in time

Question 27

Retrospective

Answer 27

Values of variables recorded backward in time

Question 28

Blind experiment

Answer 28

Subjects unaware of which treatment they are receiving

Question 29

Double Blind Experiment

Answer 29

Testing procedure designed to eliminate biased results Where identity of those receiving a test treatment is concealed from both administrators and subjects until study is completed.

Question 30

Hawthorne Effect

Answer 30

People in an experiment behave differently from how they would normally behave.

Question 31

Lack of realism

Answer 31

Subjects/treatments/setting of an experiment may not realistically duplicate the conditions we want to study.

Question 32

Noncompliance

Answer 32

Failure to conform to roles / standards

Question 33

Blocking

Answer 33

Divide subjects into groups of individuals who are similar with respect to an outside variable.

Question 34

Matched pairs

Answer 34

Special case of randomized block design. Used when experiment has two treatment conditions and subjects can be grouped into pairs. Then within each pair subjects are randomly assigned to different treatments.

Question 35

Randomized response

Answer 35

Survey technique for eliminating evasive answers.

Question 36

Leading question

Answer 36

Questions that influence the response

Question 37

Sensitive questions

Answer 37

Questions that may make someone answer dishonestly because of how they feel. (I.e. Questions about lowest grade last year).

Question 38

Classical problems (theoretical/true problems)

Answer 38

Games of chance Flipping coins, rolling dice, spinning spinners

Question 39

Empirical problems (relative frequency)

Answer 39

Run a simulation or use a random sample Use a series of trials that produce outcomes that cannot be predicted in advance

Question 40

Law of large numbers

Answer 40

As the number of trials increases, the relative frequency becomes the actual probability

Question 41

Rule #1. Probabilities are between 0 and 1

Answer 41

A +B + C = 1

Question 42

Rule #2 | Something must happen

Answer 42

As number increases should see a change

Question 43

Rule #3. Complement Rule

Answer 43

P(not A) = 1-P(A)

Question 44

Rule #4 addition rule for disjoint events

Answer 44

P(A or B) = P(A) + P(B) P(A or B) = probability that event A occurs or event B occurs or both)

Question 45

Rule #5 multiplication rule for independent events

Answer 45

P(A and B) = P(A)*P(B) P(A and B) = Probability that event A and event B occur.

Question 46

Disjoint events

Answer 46

Whether or not it is possible for the events to occur at the same time

Question 47

Independent events

Answer 47

If event A occurring does not effect the probability of event B will occur.

Question 48

Probability of at least

Answer 48

L = at least / or not P(L) = 1-P(notL)

Question 49

Rule #6 general rule of addition

Answer 49

P(A or B) = larger number P(A and B) = smaller number

Question 50

Distribution means...

Answer 50

What values the variables take and how often the variables take those values.

Question 51

Skewed right

Answer 51

Most data on left, minimal on right. (Right tail (larger values) is much longer than left tail (smaller values)) Example: distribution of salary.

Question 52

Skewed Left

Answer 52

Left tail (smaller values) is much longer than the right tail (larger values). (Example: age of death from natural causes).

Question 53

Stemplot

Answer 53

Retains actual data and organized it.

Question 54

Given that the student is male, what is the probability that he has one or both ears pierced?

Answer 54

P(E) = probability of having one or both ears pierced P(M) = male student P(E | M )

Question 55

Formal definition of probability

Answer 55

P(B | A) = P(A and B) / P(A)

Question 56

If service A has failed to deliver the document on time, what is the probability that it has arrived on time using service B.

Answer 56

P(B | not A) = P( B and not A) / P ( not A)

Question 57

Testing for independence

Answer 57

Compare the overall probability to the conditional probability. ``` Compare P(B | A) to P (B) as well as P(A | B) to P(A) or, P(B | A) to P(B | not A) ``` If the two events are equal then they are independent.