The t-test
Introduction to Using
Statistics for Hypothesis
Testing
One-sample t-test Example
Take a sample, set a confidence interval around the sample mean. Does the interval
contain the hypothesized value?
One-sample t-test Example
Standard deviation of
The t-test
Introduction to Using
Statistics for Hypothesis
Testing
One-sample t-test Example
Take a sample, set a confidence interval around the sample mean. Does the interval
contain the hypothesized value?
One-sample t-test Example
Standard deviation of
The t-test
Introduction to Using
Statistics for Hypothesis
Testing
One-sample t-test Example
Take a sample, set a confidence interval around the sample mean. Does the interval
contain the hypothesized value?
One-sample t-test Example
Standard deviation of
The t-test
Introduction to Using
Statistics for Hypothesis
Testing
Overview of the t-test
used to help make decisions about population
values.
2 main forms of the t-test: a single sample
and two samples.
One sample t-test
used to test whether a population
Statistics as a Decision Aid
Because of uncertainty (have to estimate
things), we will be wrong sometimes.
The point is to be thoughtful about it; how
many errors of what kinds? What are the
consequences?
Statistics allows us to calculate probabilities
an
Distribution shapes (a): symmetric or skewed?
4
6
5
3
Frequency
Freq u en cy
4
2
3
2
1
1
0
0
0
5
10
symmetric
15
1
2
3
4
5
6
7
skew to the right
8
9
10
Distribution shapes (b): uni- or bi-modal?
Remember: for discrete observations, the mode is the
most fr
Measures of Dispersion or
Spread
Read chapter 6 in Hampton and
Havel
Normal Curve:
one of the most important and widely used
continuous distribution.
a normal random variable
its probability distribution is called a normal
distribution.
Characteristics of
Basic Probability
Homework
Due Wednesday regardless of whether we get through the
whole lecture
Read chapter 5
Exercises 5.1-5.6
Introduction
Probability - study of randomness and uncertainty.
Historically- probability associated with games of chance.
Sim