Stat 312 Homework Problems - Week 10

This shows how valuable degrees of free dom are when

Info iconThis preview shows page 1. Sign up to view the full content.

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

Unformatted text preview: how valuable degrees of free dom are when the sample sizes are small. Section 9.3 37. Differences of the form (Outdoor – Indoor) hexavalent chromium were calculated, giving rise to the data in the table. The data are paired by location, so a paired analysis is the appropriate approach. a. The confidence interval for D = O – I is given by Indoor Outdoor D=O-I n 33 33 33 mean .231 .655 .424 s .128 .380 .387 . W e are 95% confident that the mean outdoor hexavalent chromium exceeds the mean indoor value by .287 to .561nanograms/cm 3. b. The prediction error for a newly observed difference (outdoor-indoor) in hexavalent chromium is . The 95% prediction interval for a newly observed difference of outdoor minus indoor hexavalent chromium is given by . W e are 95% confident that a newly observed house would have a difference of outdoor minus indoo r chromium between -.376 and 1.224 nanograms/cm3. 38. The sample statistics for peak stress are given in the table. a. The box plot is given at right. Peak stress has a mild positive skew for the normal strength mix. Neither box plot indicates strong non-normality. It’s pretty clear already what the answer to part (b) will be! The data...
View Full Document

This note was uploaded on 09/17/2012 for the course STAT 312 taught by Professor Chung during the Spring '04 term at University of Wisconsin.

Ask a homework question - tutors are online