A study determined that in 2009, 38 of those in a random sample ...

[Jkov05]

A study determined that in 2009, 38 of those in a random sample of 100 adult Americans had accounts with some type of social web site. In a similar survey conducted in 2012, 53 reported having accounts. Suppose that the 2012 figure was also based on a random sample of size 100. The 95 confidence interval for the difference in population proportions, , is: <--EndFragment--> >
  1.0.15  0.088
  2.0.29  0.136
  3.0.15  0.136
  4.0.29  0.88
  5.0.00  0.136

Question 2

A study by the Poultry Research Center seeks to determine if diet affects the onset of egg laying in juvenile Rhode Island Red hens. In a group of 34 hens that were fed scratch grain, 12 were laying eggs at 13 weeks of age. In a second, independent group of 25 hens that were fed on layer pellets, 4 hens were laying at 13 weeks of age. The 95 confidence interval for the difference in laying proportions at 13 weeks is:
  1.0.19  0.13
  2.0  0.13
  3.8  10
  4.0.16  0.06
  5.0.19  0.22

[tofugiraffe]

Answer to Question 1

3

Answer to Question 2

5