Answer:
6
Step-by-step explanation:
Which sampling method divides the population up into sections, randomly selects some of those sections, then chooses all the members from the selected sections to study?
Answer: The above mentioned type of sampling is called cluster sampling.
Cluster sampling is a sampling technique in which the entire population of interest is divided into clusters or groups, then the investigator randomly selects some of these clusters and all the members of these randomly selected clusters are investigated.
If we let p and t be the masses of the paper and textbook, respectively, the equations that would best represent the given in this item are:
(1) 20p + 9t = 44.4
(2) (20 + 5)p + (9 + 1)t = 51
The values of p and t from the equation are 0.6 and 3.6, respectively. Thus, each paperback weighs 0.6 pounds and each textbook weighs 3.6 pounds.