Homework Solutions 08

# Homework Solutions 08 - Solutions to Homework#8(W4150 Intro...

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

Solutions to Homework #8 (W4150 ‘Intro to Probability and Statistics’, S04) Sec. 9.7. (4) n = 30; X = 780; σ = 40; z α /2 = z 0.02 = 2.054 Hence by applying formula for CI from p.235 we obtain: ) 30 40 )( 05 . 2 ( 780 ) 30 40 )( 05 . 2 ( 780 + < < µ or 795 765 < < Sec.9.7. (6) n = 50; X = 174.5; σ = 6.9; z α /2 = z 0.01 = 2.33 (a) The confidence interval is given by the same formula as above, which in this case yields: ) 50 9 . 6 )( 33 . 2 ( 5 . 174 ) 50 9 . 6 )( 33 . 2 ( 5 . 174 + or 77 . 176 23 . 172 < < (b) By Theorem 9.1 we can be 98% sure that the error 27 . 2 50 / ) 9 . 6 )( 33 . 2 ( = < e Sec. 9.7. (7) Applying the same methods for n = 100; X = 23,500; σ = 3,900 and z α /2 = z 0.005 = 2.575 we get: (a) 99% CI for mean: 22,496 < µ < 24,504; and (b) estimation for error 1004 < e Sec. 9.7 (8) In this as well as in two next problems we use formula given in Theorem 9.1 z α /2 = z 0.02 = 2.054; e = 10; σ = 40 and so n = [(2.05)(40)/10]

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 06/02/2010 for the course IEOR SIEO W4150 taught by Professor Gallego during the Spring '04 term at Columbia.

### Page1 / 2

Homework Solutions 08 - Solutions to Homework#8(W4150 Intro...

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

View Full Document
Ask a homework question - tutors are online