slide7 - Inference on Mean, Var Unknown Replace with the...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Inference on Mean, Var Unknown ± Replace σ with the sample variance, S. ± So if the test is: ± H 0 : µ = µ 0 ± H 1 : µ≠µ 0 ± The test statistic then becomes ± ± Use normal distribution if n is large. n / S X T 0 0 µ = 2 The t Distribution ± Again, the test is: ± H 0 : µ = µ 0 ± H 1 : 0 ± The test statistic is: ± ± Where T follows a t distribution with n – 1 degrees of freedom. n / S X T 0 0 =
Background image of page 1

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

View Full DocumentRight Arrow Icon
3 Rejection region for the t-test ± For a two-tailed test: ± Reject if |t| > t α /2,n–1 ± For an upper-tail test: ± Reject if t > t α ,n–1 ± For an lower-tail test: ± Reject if t < t α ,n–1 4 Example: Tensile Adhesion Test ± The mean load at failure is assumed to no more than 10 MPa. The sample mean, in a sample size of 22, was 13.71. And, the sample standard deviation was 3.55. Should we accept the null hypothesis at the α = 0.05 level?
Background image of page 2
Background image of page 3

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

View Full DocumentRight Arrow Icon
Background image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/05/2008 for the course IE 121 taught by Professor Perevalov during the Spring '08 term at Lehigh University .

Page1 / 4

slide7 - Inference on Mean, Var Unknown Replace with the...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online