# Stats Final

## 59 terms

### statistics

methods used to collect and analyze data to make decisions

### descriptive stats

displays data using tables/graphs

### inferential stats

uses sample results to make decisions and predictions

### population

all elements being studied

### census

survey of all members of population

### data set

collection of measurements on a variable

### sample

the portion of population studied

### sample survey

survey of elements of sample

### representative sample

sample that represents characteristics of pop. as closely as possible

### random sample

sample drawing where each element has a chance of being selected

### simple random sample

all samples of same size have same chance of being selected

### survey

collection of data on elements of sample

### element

subject which information is collected

### variable

characteristic under study with changes values

### quantitative variable

variable can be measured numerically

### qualitative variable

variable cannot be measured numerically

### discrete variable

countable variable

### continuous variable

variable can assume any numerical value over an interval

### constant

fixed number in a study

### measurement

value of variable for an element

### cross-section data

data collected at same point or period of time

### time-series data

data collected at different points or periods of time

unprocessed data

### class

interval of values between two numbers

### class boundary

midpoint of upper limit and next lower limit

### symmetric histogram

identical on both sides of central point

### skewed histogram

Tail of one side of graph is larger than other

### uniform histogram

has same frequency for each class

### cumulative frequency distribution

total number values below upper boundary of each class

### outliers

very small/large values relative to majority

### grouped data

data presented in frequency distribution

### ungrouped data

data with info on each sample individually

average

middle number

### mode

most occurring number

### event

collection of one or more outcomes

### simple event

event with only one final outcome

### compound event

event with more than one outcome

### probability

likelihood of a specific event

### subjective probability

prob. based on experience or belief

### classical probability

all events have equally likely outcomes

### marginal probability

prob. of single event with consideration of another event

### conditional probability

prob. of one event given another already occurred

### mutually exclusive

events that cannot occur together

### law of large numbers

prob. approaches actual prob. as experiment is repeated

### independent events

events that do not affect each other

### dependent events

events that affect each other

### impossible event

event that cannot occur

### outcome

reuslt of an experiment

### complementary events

all outcomes except the one mentioned

### joint probability

Prob of intersection of two events

### union of events

outcomes belonging to A and/or B

### random variable

value determined by outcome of random experiment

### discrete random variable

countable random value

### continuous random variable

random variable that assumes any value

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### combinations (nCx)

number of ways x can be selected from n

### permutation (nPx)

combinations where order is important

### bernoulli trial

repetition of binomial experiment