One benefit of cluster sampling is that it Group of answer choices
a. is effective for use in school research.
b. assures limited sampling error.
c. is more generalizable than simple random sampling.
d. assures all members of the population can be in a treatment condition.

a. is effective for use in school research.

Step-by-step explanation:

Cluster sampling is the sampling whereby we pick random few sample from the population to serve as the sample population called cluster. This cluster usually have uniform characteristics among them.

The main advantage of cluster sampling is that it is effective school research because of its cheapness and doesn't require much resources during the sampling process.

The other options are not correct because Cluster sampling have High sampling error and its biased sample.

1/3 + 1/3 ≠ 2/6 because 1/3 alone = 2/6  

step by step explanation:

1/3 + 1/3 = 2/3       2/3=4/6