USU
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Author:
Anonymous
ID:
25236
Filename:
USU
Updated:
2010-06-29 15:55:50
Tags:
Statistics
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Description:
Module 8
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What is statistics
a tool that we use to make objective decisions from subjective data
Uses for stats
represent data
descriptive
correlation
inferential
Data
info collected on subject
usually numbers - height, weight, scores
sometimes words or categories
Representation
graphs or charts
Descriptive
Measures central tendency
Measures variability
Measure of Central Tendency
mean
median
mode
Measure of Variability
range
standard deviation
Mean
aka average
add points and divide by number of data points
Median
Order data points from least to greatest
median is middle
Mode
most frequently occuring data point in series
Range
difference between the least and greatest data point in series
Standard Deviation
tells how tightly all data points are clustered around mean in series of data. this is a measure of variability
data distribution
mean weight of students at 2 different schools
graph the data
Correlation
measure relationship between two varaibles cannot measure cause and effect
Inferential
allow us to test hypothesis in an experiment for cause and effect while comparing
null hypothesis
keeps bias out of experiement
t-test
used to determine if the means of two samples are significantly different
P value
level of significance of test
he probability that two samples are likely to have come from the same two underlying populations that have the same mean