Stats Ch1 and 2.1 Exam

data

information from observations

statistics

science of collecting data

parameter

numerical description of population

population data set

all outcomes (general audience) (typically the opening statement)

sample data set

subset/part of population

descriptive statistics

(restate) summary of data

inferential statistics

draw conclusions on populations based on a sample

nominal level of measurement

qualitative only, just names data

ordinal level of measurement

data meaningfully ranked

inherent zero

implies “none” or the absence of something

non inherent zero

represents a position on the scale (0 degrees C)

random sampling

every member of the population has an equal chance of being selected

simple random sample

every possible sample has the same chance of being selected

systematic sampling

everyone has a number and can be picked randomly

convenience sample

(biased) whoever is easiest access

quantitative

numerical data

interval level of measurement

noninherent zero (data can be calculated) and ranked meaningfully (equal spacing between values)

ratio level of measurement

(inherent zero) one data point can be a multiple of another

census

count of an entire population

stratified sample

stratas/groups of similar people are formed, and data is taken from each group

cluster sampling

stratas/groups of similar people are formed, only some give data

frequency distribution

table displaying classes of data

frequency

the amount of times a number is entered into a class of data

class width

class range divided by the amount of classes (difference between consecutive lower limits)

class range

difference between maximum and minimum data entries

class boundaries

separates classes without forming gaps (usually 0.5 below lower limit and 0.5 above upper limit)

cumulative frequency graph or o-give

line graph displaying cumulative frequency of class (dotted line to 2nd boundary - start there and only continuous on left)

polygon

line graph (continuous on both ends)

histogram

bar graph

cumulative frequency

all data points thus far

midpoint

upper + lower/2