Stat Flashcards
(21 cards)
Population
Entire collection of objects, like all UNLV students
Sample
A subset of the population, to understand the entire population, like UNL students that have taken a STAT class
Sampling issues
-selection bias
-non-response bias
-sampling variation
Simple random sample
A collection of population items that are likely to make up the sample (like a random generator selecting people)
Observational study
experimenter observes factors as they are, w no control over them
designed experiment
experimenter controls the value of factors
variable
-characteristic of interest
-age, gender, blood group, etc
individual
object on which measurement is taken, like people
pareto chart
a bar chart with decreasing order of frequencies
describing a histogram
-shape
-center
-modes (unimodal, bimodal, multimodal)
-spread
-outliers
measures of central tendency = quantitative measure
-mean
-medan
-mode
measures of variability
-range
-sample variance and standard deviation
-inter-quartile range
measures of relative standing
-quartiles
-percentiles
-z score
inter-quartile range
range of the middle 50% of data
quartiles
divides data into 4 equal parts
first quartile
-lower quartile
-median for all observations below the median
third quartile
-upper quartile
-median for all observations above the median
second quartile
the median
percentiles
divides data into 100 equal parts
statistic
numerical summary of a sample
parameter
numerical summary of a population
