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:
A)0.19 ± 0.13
B)0 ± 0.13
C)8 ± 10
D)0.16 ± 0.06
E)0.19 ± 0.22

Question

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: ​
A)0.19 ± 0.13
B)0 ± 0.13
C)8 ± 10
D)0.16 ± 0.06
E)0.19 ± 0.22

Quizplus · Accepted Answer

The difference in proportions is calculated as (12/34) - (4/25) = 0.19. The confidence interval is given as 0.19 ± 0.22.

A Study by the Poultry Research Center Seeks to Determine