Question

Eleanor Rigby the Sock-Eating Mutt wants to know whether topical or oral flea preventative measures are more effective for treating fleas in dogs. From a list of 14756 dogs, she finds 60 that are suitable for her study. She divides the 60 dogs within her study into three groups: small dogs (< 20 lbs), medium dogs (20 to 60 lbs), and large dogs (> 60 lbs). There are 20 dogs in each group. She randomly assigns 10 dogs from each size group to receive an appropriate dosage of the topical flea preventative, and the other 10 to receive the oral flea preventative. Which of the following best describes the design of her study?

A. Cluster design 0.
B. Stratified design 0.
C. Simple random design 0.
D. Completely randomized design 0.
E. Randomized block design 0.

Answer 1

Stratified Design

Explanation:

Eleanor Rigby's research is about, whether 'topical or oral flea preventative measures are more effective for treating fleas in dogs'

Sampling is the technique of selecting study units for conducting the research. She draws a sample of total 60 dogs suitable for her study.

Stratified sampling means sample arrangement in a structure of subgroups called 'stratas'. The stratas are similar within themselves & differ from each other. She divides sample dogs into three stratas based on their size & weight. And; similar weight & size dogs are arranged in their corresponding 'small', 'medium' or 'large' sized dogs strata. So, the dogs stratas are similar within themselves & differ from each other, in regards to their weight & size. Hence, she has used Stratified Design