ch09_Class Notes till 11.16.09_1

ch09_Class Notes till 11.16.09_1 - 9-1 Hypothesis Testing...

Info icon This preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
9-1 Hypothesis Testing 9-1.1 Statistical Hypotheses Definition Statistical hypothesis testing and confidence interval estimation of parameters are the fundamental methods used at the data analysis stage of a comparative experiment, in which the engineer is interested, for example, in comparing the mean of a population to a specified value.
Image of page 4
9-1 Hypothesis Testing 9-1.1 Statistical Hypotheses For example, suppose that we are interested in the burning rate of a solid propellant used to power aircrew escape systems. Now burning rate is a random variable that can be described by a probability distribution. Suppose that our interest focuses on the mean burning rate (a parameter of this distribution). Specifically, we are interested in deciding whether or not the mean burning rate is 50 centimeters per second.
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
9-1 Hypothesis Testing 9-1.1 Statistical Hypotheses null hypothesis alternative hypothesis One-sided Alternative Hypotheses Two-sided Alternative Hypothesis
Image of page 6
Hypotheses are always statements about the population or distribution under study, not statements about the sample. The value of the population parameter specified in the null hypothesis (50 centimeters per second in the above example) is usually determined from past experience or knowledge of the process, or even from previous tests or experiments from some theory or model regarding the process under study from external considerations, such as design or engineering specifications, or from contractual obligations.
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
A procedure leading to a decision about a particular hypothesis is called a test of a hypothesis. A hypothesis-testing procedure should be developed with the probability of reaching a wrong conclusion in mind. The null hypothesis will always be stated so that it specifies an exact value of the parameter (as in the statement H 0 : μ = 50 centimeters per second)
Image of page 8
Exercise 9.1 In each of the following situations, state whether it is a correctly stated hypothesis testing problem and why. Yes, because the hypothesis is stated in terms of the parameter of interest, inequality is in the alternative hypothesis, and the value in the null and alternative hypotheses matches.
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Exercise 9.1 - Continued In each of the following situations, state whether it is a correctly stated hypothesis testing problem and why. No, because the inequality is in the null hypothesis.
Image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern