7.3 #22,33

#22

The American Taxpayer Relief Act of 2012 was passed by the U.S. Congress on January 1, 2013. This act helped address what became famously known as the "fiscal cliff" crisis. However, during the last months of 2012, heated debates concerning the crisis were ongoing in Congress, and there was growing concern political gridlock was preventing solution of the crisis by the end-ofyear deadline. In mid-December, a USA Today- Gallup poll reported that only 18% of a sample of 1025 adult Americans approved of the job Congress was doing in working toward a solution to the looming fiscal cliff. Calculate a two-sided confidence interval using a 99% confidence level for the proportion of all U.S. adults who approved of the congressional handling of the crisis in December 2012.

#33

33. Relative density was determined for one sample of second-growth Douglas fir 2 3 4s with a low percentage of juvenile wood and another sample with a moderate percentage of juvenile wood, resulting in the following data ("Bending Strength and Stiffness of Second-Growth Douglas Fir Dimension Lumber," Forest Products J., 1991: 35-43):

Type n x s Low 35 .523 .0543 Moderate 54 .489 .0450

Estimate the difference between true average densities for the two types of wood in a way that conveys information about reliability and precision.

Devore, Jay L.; Farnum, Nicholas R.; Doi, Jimmy A.. Applied Statistics for Engineers and Scientists (p. 317). Cengage Learning. Kindle Edition.