HW8_skeleton

9.1

• 1. point estimate
• 2. level of confidence; (1-a) x 100%
• 3. False
• 4. critical value
• 5. increases
• 6. decreases
• 7. 90% = 1.645
• 8. 99% = 2.575
• 9. 98% = 2.33
• 10. 92% = 1.75
• 11. p-hat = 0.225; E = 0.024; x = 270
• 12. p-hat = 0.0625; E = 0.0115; x = 70
• 15. (0.416, 0.254)
• 16. (0.319, 0.481)
• 21. 3. We are 95% confident the proportion of adult Americans suring the Great Depression who believed wages paid to workers in industry were too low was between 0.52 and 0.58
• 1. p-hat = 0.181

  2. 341.8 >/= 10 and the sample is less than 5% of the population

  3. (0.168, 0.194)

  4. We are 90% confident that the proportion of adult Americans aged 18 or older who donated blood in the last two years is between 0.168 and 0.194.

• 1. p-hat = 0.430

  2. 282.6 >/= 10 and the sample is less than 5% of the population

  3. (0.401, 0.459)

  4. We are 95% confident the proportion of workers and retirees in the United States 25 years of age and older who had less than $10,000 in savings is between 0.401 and 0.459.