Representative sample
A part of the population used to gather information,
representing the entire population.
Random sampling
Allows individuals from each group within a population to be represented in the sample set.
Inference
A conclusion, estimate, or prediction based on data.
data
facts or information used usually to calculate, analyze, or plan something
population
The entire group of items or individuals from which the samples under consideration are taken
dot plots
a statistical chart consisting of data points plotted on a fairly simple scale, typically using filled in circles.
box plots
A method of displaying a distribution of data values by using the median, quartiles, and extremes of the data set.
histograms
A type of bar graph used to display numerical data that have been organized into equal intervals.
Center
The one number that summarizes data by giving the middle or center value
mean
The "average" or "fair share" value for the data. The mean is also the balance point of the corresponding data distribution.
median
The value for which half the numbers are larger and half are smaller. If there are two middle numbers, this is the mean of the two middle
numbers
Interquartile range
The range, or difference, in values of the first and third
quartiles.
Range
A measure of spread for a set of data. To find this measure, subtract the smallest value from the largest value in a set of data
Spread
The one number that summarizes the variation in the data. This can be measured by the range or interquartile range.