{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

class08-2-handouts

# class08-2-handouts - PSTAT 120B Probability Statistics...

This preview shows pages 1–7. Sign up to view the full content.

PSTAT 120B - Probability & Statistics Class # 08-2- Sample size and CIs Jarad Niemi University of California, Santa Barbara 19 May 2010 Jarad Niemi (UCSB) Sample size and CIs 19 May 2010 1 / 14

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

View Full Document
Class overview Announcements Announcements Homework Homework 6 due Monday, 24 May @ 4pm in SH 5521 Mid-term II #6 was incorrect in the answer key, so if you have answer c and have it marked incorrect, see me. Jarad Niemi (UCSB) Sample size and CIs 19 May 2010 2 / 14
Class overview Goals Calculating Type II error probabilities Sample size of z tests Relationship to confidence intervals Jarad Niemi (UCSB) Sample size and CIs 19 May 2010 3 / 14

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

View Full Document
Sample size Review Large-sample α -level hypothesis tests H 0 : θ = θ 0 H a : θ > θ 0 (upper-tail alternative) θ < θ 0 (lower-tail alternative) θ 6 = θ 0 (two-tailed alternative) Test statistic : Z = ˆ θ - θ 0 σ ˆ θ Rejection region : z > z α (upper-tail RR) z < - z α (lower-tail RR) | z | > z α/ 2 (two-tailed RR) Jarad Niemi (UCSB) Sample size and CIs 19 May 2010 4 / 14
Sample size Review Any kind of decision you make under uncertainty can have 4 possible outcomes. H 0 True False Test result Reject H 0 Type I error True positive Do not reject H 0 True negative Type II error α = P(type I error) β = P(type II error) 1 - β = power of the test Jarad Niemi (UCSB) Sample size and CIs 19 May 2010 5 / 14

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

View Full Document
Sample size Example Exercise 10.34) A random sample of 500 measurements on the length of stay in hospitals had sample mean 5.4 days and sample standard deviation
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}