To investigate if standing up while studying affects performance in an algebra class, a teacher assigns half of the 30 students in his class to stand up while studying and assigns the other half to not stand up while studying. to determine who receives which treatment, the teacher identifies the two students who did best on the last exam and randomly assigns one to stand and one to not stand. the teacher does the same for the next two highest-scoring students and continues in this manner until each student is assigned a treatment. which of the following best describes this plan?
a. this is a completely randomized experiment.
a. this is a cluster sample.
c. this is a stratified random sample.
d. this is an experiment with blocking.
e. this is an observational study

it apply by theyre artifacts

manifest functions are the recognized and intended consequences of any social pattern, while latent functions are those unrecognized and unintended consequences. to analyze the manifest functions of any social institution, we have to study its contribution to the continuation of a group, community, or society.

muslims have taken his goods and products to different parts of asia an indonesia. sometimes just traveled and trade, but in other occasions, stayed in the place and made a living.

trade was the key for muslims economies to prosper. their commerce routes reached far places like malaysia and java in the 11th century.

another important factor for prosperity was that muslim states served as the middle point for european traders.

they used to travel by land but sailing the seas -the indian ocean- really increase the exportation of products.