At a college there are 120 freshmen, 90 sophomores, 110 juniors, and 80 seniors. A school administrator selects a random sample of 12 of the freshmen, a random sample of 9 of the sophomores, a random sample of 11 of the juniors, and a random sample of 8 of the seniors. She then interviews all the students selected. Identify the type of sampling used in this example.

Stratified sampling

Step-by-step explanation:

The is a type of sampling in which the population of interest is divided into subpopulations and then each subpopulation is randomly sampled.

In this case study, instead of just doing a random sampling of all students, the research divided the population of all students into subpopulations which includes freshmen, sophomores, juniors and seniors and then she makes a random sampling of each of these subpopulations.

  A. 3x+2y is less than or equal to 3 and 3x+4y is greater than or equal to 2.

Step-by-step explanation:

Both lines on the graph are solid, so both inequalities must include the "or equal to" case. (This eliminates choices B and C.)

The graph is shaded below the line 3x+2y=3, so the corresponding inequality is 3x +2y ≤ 3. (This eliminates choice D.)

The correct system of inequalities is choice A:

The point (-2, 3) is in the solution set for both inequalities.