HW8_skeleton

9.1

• 1. point estimate
• 2. level of confidance
• 3. False
• 4. Critical value
• 5. Increases
• 6. Increases
• 7. 1.645
• 8. 2.575
• 9. 2.33
• 10. 1.75
• 11. P hat= .225 E= .024 n=270
• 12. p hat= .0625 E=.0115 n=70
• 15. Lower bound= .146 Upper bound=.254
• 16. Lower bound=.319 Upper bound=.481
• 21. A. Flawed, no interval included. B. Flawed, The level of confidance is varrying which makes no sense C. Correct D. Flawed, Confidance interval being mixed up with the norm for other samples, which is not true.
• 1. P hat = .181

  2. NPhat(1-Phat)= 341.83.>10 and sample is less than 5 percent of population

  3. Lowe bound=.168 Upper bound=.194

  4. We are 90 percent confidant that the number of americans who donated blood in the last two years is between .168 and .194.

• 1. P hat=.430

  2. NPhat(1-Phat)= 282.6>10 and sample is less than 5% of population

  3. Lower Bound=.402 Upper bound= .459

  4. We are 95% confidant that retirees in the US 25 years or older who have less than $10,000 in savings is between .402 and .459