文档介绍：CHAPTER 10: Hypothesis Testing, One Population Mean or Proportion
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Introduction to Business Statistics
fourth edition, by Ronald M. Weiers
Presentation by Priscilla Chaffe-Stengel
Donald N. Stengel
© 2002 The Wadsworth Group
Chapter 10 - Learning Objectives
Describe the logic of and transform verbal statements into null and alternative hypotheses.
Describe what is meant by Type I and Type II errors.
Conduct a hypothesis test for a single population mean or proportion.
Determine and explain the p-value of a test statistic.
Explain the relationship between confidence intervals and hypothesis tests.
© 2002 The Wadsworth Group
Null and Alternative Hypotheses
Null Hypotheses
H0: Put here what is typical of the population, a term that characterizes “business as usual” where nothing out of the ordinary occurs.
Alternative Hypotheses
H1: Put here what is the challenge, the view of some characteristic of the population that, if it were true, would trigger some new action, some change in procedures that had previously defined “business as usual.”
© 2002 The Wadsworth Group
Beginning an Example
When a robot welder is in adjustment, its mean time to perform its task is minutes. Past experience has found the standard deviation of the cycle time to be minutes. An incorrect mean operating time can disrupt the efficiency of other activities along the production line. For a recent random sample of 80 jobs, the mean cycle time for the welder was minutes. Does the machine appear to be in need of adjustment?
© 2002 The Wadsworth Group
Building Hypotheses
What decision is to be made?
The robot welder is in adjustment.
The robot welder is not in adjustment.
How will we decide?
“In adjustment” means µ = minutes.
“Not in adjustment” means µ ¹ minutes.
Which requires a change from business as usual? What triggers new action?
Not in adjustment - H1: µ ¹ minutes
© 2002 The Wadsworth Group
Types of Error
No error
Type II erro