Vocabulary

Question 1

Sample

Answer 1

Set of observations drawn from a population

Question 2

Categorical variable (qualitative)

Answer 2

Take on values that are names or labels (color of a ball, breed of dog)

Question 3

Quantitative variable

Answer 3

Numerical; represent a measurable quantity (population: number of people)

Question 4

Categorical graphs

Answer 4

Bar graph

Pie chart

Question 5

Quantitive graphs

Answer 5

Box and whisker plot
Scatter plot
Dot plot
Histogram
Stem and leaf plot

Question 6

Independence

Answer 6

Events are independent when one outcome does not affect probability or occurrence of the other

Question 7

Shape

Answer 7

Distribution of a pattern of data in a sample (quantitive)

Symmetry, number of peaks, skewness, uniform

Question 8

Center

Answer 8

Median of distribution

Question 9

Spread

Answer 9

Variability of data
Wide range -> wide spread
Small range -> small spread

Question 10

Mode

Answer 10

Most frequent occurring value in a population/sample

Question 11

Uniform

Answer 11

All observations equally spread across range of distribution

Question 12

Symmetric

Answer 12

Used to describe shape

Question 13

Skewed (left vs right)

Answer 13

Skewed right: fewer observations in higher values

Skewed left: fewer observations in lower values

Question 14

Outliers

Answer 14

Data point that differs greatly from other values in a sample

Question 15

Median

Answer 15

Measure of central tendency

Smallest->largest, number in middle=median

Question 16

Range

Answer 16

Difference between biggest and smallest random variable

Question 17

Quartiles

Answer 17

Divide a rank-ordered data set into four equal parts

Question 18

Percentile

Answer 18

Values that divide a rank-ordered set of elements into 100 equal parts

Question 19

Mean

Answer 19

Average score

Sum of individual scores divided by number of individuals

Question 20

Variance

Answer 20

Numerical value of how widely individuals value from the mean (standard deviation)^2

Question 21

Standard deviation

Answer 21

Numerical value of how widely individuals vary from the mean

Question 22

Parameter

Answer 22

Measurable characteristic of a population (mean, standard deviation)

Question 23

Statistic

Answer 23

Characteristic of a sample

Question 24

Sampling distribution

Answer 24

Probability distribution of the statistic for a sample

Question 25

Resistant statistic vs nonresistant

Answer 25

A statistic is resistant of changing data does not change the statistic drastically Nonresistant: changes with data Mean: nonresistant Median: resistant

Question 26

Z-score

Answer 26

How many standard deviations an element is from the mean

Question 27

Empirical rule

Answer 27

When a random independent trial is repeated under the same conditions, the fraction of trials that result in a given outcome converges to a limit as number of trials grows without bounds

Question 28

Response variable

Answer 28

Quantity that is questioned in the study

Question 29

Explanatory variable

Answer 29

Factor that can influence the response variable

Question 30

Lurking variable

Answer 30

Variable that eliminates extraneous variables for the observed relationship between the independent and dependent variables

Question 31

Simulation

Answer 31

Representation of something; not the real thing

Question 32

Trial

Answer 32

A repetition of an experiment

Question 33

Sample survey

Answer 33

Study that obtains data from a subset of a population

Question 34

Bias

Answer 34

Tendency of a measurement process to over/underestimate the value of a population parameter

Question 35

Randomization

Answer 35

Using chance methods to assign subjects to treatments (lurking variables distributed by chance)

Question 36

Sample size

Answer 36

Number of elements in a sample from a population

Question 37

Census

Answer 37

Study that obtains data from every member of a population

Question 38

Simple random sample (SRS)

Answer 38

Population has n objects | Sample has n objects; possible samples of n subjects are equally likely to occur

Question 39

Observational study

Answer 39

Research does not control how subjects are assigned to groups or which treatments groups receive (Sample survey)

Question 40

Experiment

Answer 40

Controlled study; subjects assigned to groups, treatments assigned

Question 41

Placebo

Answer 41

Neutral treatment that has no "real" effect on the dependent variable

Question 42

Sample space

Answer 42

Set of elements that represents all possible outcomes of a statistical experiment

Question 43

Discrete random variable

Answer 43

Variable whose set of possible values is countable

Question 44

Continuous random variable

Answer 44

A variable that can take any value between minimum and maximum values

Question 45

Population

Answer 45

Total set of observations that can be made