12. There are 435 representatives in the 113th session of the U.S. House of Representatives. On the website www.house.gov, you can find an alphabetized list of the 435 congresspersons. Suppose that the alphabetized list is indexed 1 through 435. Use systematic random sampling to obtain a sample of 15 representatives and identify exactly which numbered representatives that should be included in the sample.

13. A small company of 1,000 people wants to find out how they are saving for retirement.Use the table of age classes to find a proportional stratified random sample of 50 people.

Age Number of People

20-29 160

30-39 220

40-49 240

50-59 200

60+ 180

14. The university housing office has separate lists of dormitory residents by class level. Use the table to find a stratified sample of 30 dormitory residents with proportional allocation.

Class level Number of dorm residents

Freshman 128

Sophomore 112

Junior 96

Senior 48