Mathcad - UF-ESI-6321-04-04

Mathcad - UF-ESI-6321-04-04 - UF-ESI-6321...

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

View Full Document Right Arrow Icon

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

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

Unformatted text preview: UF-ESI-6321 UF-ESI-6321-04-04.xmcd page 1 of 2 4.4 A company manufacturing stereo equipment claims that their personal CD player can be used for approximately t := 8 hr of continuous play when used with alkaline batteries. To provide this estimate, the company tested n := 35 CD players with new alkaline batteries and recorded the time at which the batteries in the players "lost power." The average time was Xbar := 8.3 hr with a sample standard deviation of S := 1.2 hr (a) Construct a 95% confidence interval for the mean time until a new alkaline battery used in the CD player loses power. The value of n exceeds 30 which makes this analysis valid. Z95 := 1.960 upper := Xbar + Z95 = 8.7 hr := Xbar - Z95 = 7.9 hr S n upper S n lower lower Luther Setzer 1 NASA Pkwy E Stop NEM3, Kennedy Space Center, FL 32899 (321) 544-7435 UF-ESI-6321 UF-ESI-6321-04-04.xmcd page 2 of 2 (b) Determine the required sample size in order to estimate the mean time until a new alkaline battery used in the CD player loses power to within 10 minutes at the 99%confidence level. t := 10 min t = 0.167 hr Z99 := 2.576 upper := Xbar + t = Xbar + Z99 S n S n upper Xbar + t = Xbar + Z99 t = Z99 S n n := ceil Z99 t S 2 n = 344 The value of n exceeds 30 which makes this analysis valid. Luther Setzer 1 NASA Pkwy E Stop NEM3, Kennedy Space Center, FL 32899 (321) 544-7435 ...
View Full Document

This note was uploaded on 05/12/2010 for the course ESI 6321 taught by Professor Josephgeunes during the Spring '07 term at University of Florida.

Page1 / 2

Mathcad - UF-ESI-6321-04-04 - UF-ESI-6321...

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

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