Summarizing Data Flashcards
variable
an observable trait or character which for different individuals can assume different values, e.g., height
Variate
an individual measurement of a variable (my height, your height, etc.)
population
a set of variables (counts, measurements, or characteristics) about which relevant inquiries are to be made
Sample
any subset of a statistical population
Parameter
any quantitative measure which seems to characterize a population (µ)
Statistic
any quantitative measure which seems to characterize a sample (xbar) Estimates the parameter
Random sample
each member of a population has an equal and independent chance of being selected
What are the subgroups of discrete variables
Categorical (Nominal) and Ordinal
What are the subgroups of discrete variables
Categorical (Nominal) and Ordinal
Variate
an individual measurement of a variable (my height, your height, etc.)
population
a set of variables (counts, measurements, or characteristics) about which relevant inquiries are to be made
Dichotomous categorical discrete variable
Only 2 variables. Ex: male or female
Parameter
any quantitative measure which seems to characterize a population (µ)
Statistic
any quantitative measure which seems to characterize a sample (xbar) Estimates the parameter
Random sample
each member of a population has an equal and independent chance of being selected
Mode
the most common value
What are the subgroups of discrete variables
Categorical (Nominal) and Ordinal
Categorical discrete variables
Not Rank able Ex: State of residence: GA, FL, SC… Can be Dichotomous
Ordinal discrete variable
Rank able discrete variables Ex: short, average, tall
Continuous Variable
Can have any potential value for precision purposes Ex: height 5 feet 11. 33333333…. inches
Dichotomous categorical discrete variable
Only 2 variables. Ex: male or female
What are the measures of central tendency
Mean, median, mode
Mean
Mean (µ is population mean, X- is sample mean) (“average”) Formula!!! ΣXi = summation of all cases n = number of cases
Median
the middle measurement in an order set of data (X (n+1)/2)
Mode
the most common value
Range
Maximum value - Minimum value
What are the measures of variability and dispersion
Range and Quartiles
Quartile equation
Q1 = X(n+1)/4
interquartile range equation
Q3-Q1
Standard varience
“sum of squares”

Standard deviation
- The average dispersion of the variates about the mean
- s is sample SD, σ is population SD
- (xbar is sample mean, µ is population mean)

difference between a bar graph and histogram
Bar graphs demonstrate categorical data and there are spaces btwn the bars
Histogram bars usually tough eachother, are displayed in a certain way (smallest to largest) and demonstrates continuous data