A student conducts a survey to determine which students at the high school completed an algebra course during their freshman year. 49, 34, and 48 students are selected at random from the Sophomore, Junior, and Senior classes. Each class has a population of 496, 348, and 481 respectively. Which type of sampling did the student use?

stratified

random

cluster

systematic

Respuesta :

Answer

Option A - Stratified sampling

Explanation

The student used Stratified sampling as in the following process the student divided the students of the high school into equal subgroups before sampling. Then a random sample is drawn from each group. Members in Sophomore, Junior, and Senior classes may not be fixed as they are picked on random bases. However, the objective is to improve the accuracy of the sample when the population size is too large.