# Shared Flashcard Set

## Details

Statistics Terms for L.Van Jones' book,
31
Management
01/12/2011

Term
 Bias
Definition
 Tendency to favor the selection of certain sample elements or events over other sample elements or events
Term
 Random Sample
Definition
 Each and every element in the population must have an equal and independent chance of selection.
Term
 Population
Definition
 The entire collection of all observations of interest to the researcher
Term
 Sample
Definition
 Representative portion of the population selected for study
Term
 Sampling Error
Definition
 Difference between the sample mean and the population mean
Term
 Parameter
Definition
 Any descriptive measure of the entire population.
Term
 Statistic
Definition
 Any descriptive measure of the sample
Term
 Central Tendency
Definition
 The tendency of the distribution to fall close to a central point or middle point. Examples include arithmetic mean, median, and mode.
Term
 Mean
Definition
 Arithmetic Average
Term
 Median
Definition
 The value in the middle.
Term
 Mode
Definition
 The value that occurs most often
Term
 Dispersion
Definition
 Range, Average Deviation, Variance, Standard Deviation, Percentiles, Quartiles, Deciles,
Term
 Range
Definition
 Difference between high and low values
Term
 Average Deviation
Definition
 Difference between the mean and each of the individual values in the data set. Always zero. First step in determining the variance.
Term
 Variance
Definition
 The mean of the squared deviations around the mean. Only calculated so we can determine standard deviation.
Term
 Standard Deviation
Definition
 Square root of the variance. Most important.
Term
 Percentiles
Definition
 divides the data set into 100 equal pieces
Term
 Quartiles
Definition
 divides the data set into 4 equal pieces
Term
 IQR
Definition
 Inter-Quartile Range the middle fifty-percent of the data set. Difference between the 25th and 75th percentile value
Term
 Deciles
Definition
 Divides data set into 10 equal pieces.
Term
 Variable
Definition
 Characteristic of the population or sample that is being examined in the statistical study
Term
 Quantitative Variable
Definition
 Expressed Numerically - weights, heights, age, etc.
Term
 Continuous Data Sets
Definition
 Quantitative Variable where values can take on a range of values (usually not whole numbers)
Term
 Discrete Data Sets
Definition
 Quantitative Variable that is generally expressed in whole numbers.
Term
 Qualitative Variable
Definition
 Expressed Non-numerically like gender or religious preference.
Term
 Raw Data Set
Definition
 data set that is unorganized.
Term
 Grouped (Frequency Distribution) Data Set
Definition
 Data set that is sorted and grouped into classes
Term
 Class
Definition
 Section of a Grouped(Frequency Distribution) Data Set
Term
 Determine Number of Classes
Definition
 2^C >= N where C is number of classes and N is the number of population observations. 'N' would be 'n' in a sample data set
Term
 Class Interval
Definition
 CI = (Largest Value - Smallest Value)/Number of Classes. You have some leeway here
Term
 Class Midpoint
Definition
 Lowest Value of Class + Highest Value of Class divided by 2
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