A gardener wants to know if soaking seeds in water before planting them increases the proportion of seeds that germinate. To inv
estigate, the gardener will assign 50 seeds to be soaked before planting and 50 seeds to be planted without being soaked. After two weeks, the gardener will record how many seeds in each group germinated and construct a 95 percent confidence interval for the difference in proportions. Which of the following conditions for inference should be met? I. The seeds should be randomly assigned to a treatment.
II. The group sizes should be less than 10 percent of the population sizes.
III. The number of successful seeds and unsuccessful seeds in each group should be at least 10.
a. I only
b. II only
c. III only
d. I and III only
I. The seeds should be randomly assigned to a treatment.
III. The number of successful seeds and unsuccessful seeds in each group should be at least 10.
The distribution of difference between two sample proportions :
Given :
Proportion 1 = P1 ;
Proportion 2 = P2 ;
Sample assignment for both samples 1 and 2 into the different treatment groups should be randomized, that is a simple random sampling of subjects into the treatment and control group. The sample design for difference between two sample proportions should be independent.
Finally each of the two proportions P1 and P2 should record a minimum of 10 successes and 10 non - successful Occurrences.
You have a 1/2 (or 50 percent) chance of picking a cheese sandwich at random out of your total of 8 sandwiches, 4 out of which are cheese. Simplifying the fraction, you'd get 1/2 probability. Hope this helps!
