Hw8Sol

# Hw8Sol - Homework Solutions Assignment Number 8 Due March...

This preview shows pages 1–2. Sign up to view the full content.

Homework Solutions Assignment Number 8 Due March 12, 2007 Section 7.4. Problem 25. As n increases, Student t pdfs converge to the standard normal pdf, f Z ( z ). (See problem 7.3.13) Section 7.5. Problem 3. (a) 2.088 (b) 7.261 (c) 14.041 (d) 17.539 Problem 5. χ 2 . 95 , 200 . = 200 1 - 2 9(200) + 1 . 64 s 2 9(200) ! 3 = 233 . 9 . Problem 8 G . If n = 19 and σ 2 = 12 . 0, 18 S 2 12 . 0 has a χ 2 distribution with 18 df, so . 95 = 1 - . 05 = P ( χ 2 . 05 / 2 , 18 χ 2 18 χ 2 1 - . 05 / 2 , 18 ) = P ± 8 . 231 18 S 2 12 . 0 31 . 526 ² = P (5 . 49 S 2 21 . 02). Problem 15 G . Test H 0 : σ 2 = 1 versus H 1 : σ 2 > 1. The sample variance is 30(19195 . 7938) - (758 . 62) 2 30(29) = 0 . 425 The test statistic is χ 2 = 29(0 . 425) 1 = 12 . 325 . The critical value is χ 2 . 95 , 29 = 42 . 557. Since 12 . 325 < 42 . 557, we accept the null hypothesis and assume the machine is working properly.

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 03/23/2008 for the course MATH 181A taught by Professor Xu,lily during the Spring '07 term at UCSD.

### Page1 / 2

Hw8Sol - Homework Solutions Assignment Number 8 Due March...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online