Test 1 Flashcards
Categorical data
Data that can be grouped by non numerical categories
Ex: blonde hair
Quantitative data
Data presented with numbers
Descriptive statistics
Describes data to make it easy to understand
Ex: graphs, tables
Population
Set of all elements of interest in a particular study
Sample
A subset of population
Statistical inference
Uses sample characteristics to make predictions about the population
Frequency distribution
Table summary showing the NUMBER of observations in each categories
Ex 5/4 Texas students
Relative frequency
The PERCENTAGE of observations belonging to a class
Ex: 30% of Texas students
Steps for a frequency distribution table
1) find K
2) find width
3) find class limits
Histogram
Bar graph where classes are marked on the horizontal axis and class frequencies are marked on vertical axis. It provides info about the shape of the distribution
Scatter diagram
Graphical display of the relationship between quantitive variables
Trendline
A line that provides an approximation of the relationship between two variables
What’s does ⛎ (meu) stand for?
Population mean
What does X bar stand for?
Sample mean
Parameter
A characteristic of a population
Statistic
A characteristic of a sample
What does Q squared stand for?
Population variance
What does S squared stand for?
Sample variance
What does Q stand for?
Population standard deviation
What does S stand for
Sample standard deviation
Z score
The number of standard deviations a data value is from the sample mean
Chebyshevs theorem
Allows us to make statements about the percentage of data values that must be I think specified number of standard deviations of the mean
