Test 1 Flashcards
know all definitions and formulas (31 cards)
population
The entire collection of individuals or objects which information is desired
Perimeter
a number that describes a population (true #/outcome)
sample
a subset of the population, selected for study in some prescribed manner
statistic
a number that describes a sample
descriptive statistics
organizing/ summarizing data so it can be understood
Inferential Statistics
making generalizations from a sample to population
observation/case
an individual entity in a study
variable
a characteristic that may differ among individuals
frequency table
count how many observations fall into each category
relative frequency table
calculate the proportion of observations in each category
proportion
count/ total (normally a decimal)
dot plot
displays individual data value along the x axis and uses dots to represent the frequencies
percentage
count/total*100%
histograms
displays data range along the x axis and uses rectangular bars to represent frequencies
what is SOCS?
shape, outliers, center and spread
“how does this distribution look like?”… what do you respond with?
You respond with SOCS
what is a histogram for?
numerical data
If the distribution is: symmetric w/ no outliers, what do you use?
mean(center) and standard deviation(spread)
If the distribution is: skewed and/or has outlier, what do you use?
median(center) and IQR(spread)
mean
the average of a set of observations
median
value of middle observation when observations are listed in ascending/ decsending order
what are the three measures of spread?
range, st. dev, IQR
range
R= max /data value - min/data value
standard deviation
of a variable is a measure characterizes how spread apart the values of a variable in a data set are