Donald is studying the eating habits of all students attending his school. He samples the population by dividing the students into groups by grade level and randomly selecting a proportionate number of students from each group. He then collects data from the sample. Which type of sampling is used?

a. Systematic sampling
b. Convenience sampling
c. Stratified sampling
d. Cluster sampling

c. Stratified sampling

Step-by-step explanation:

Stratified sampling is a sampling method in which the studied population is divided into separate groups or subgroups known as strata, there after a simple random sample can then be drawn from each separate or subgroups.

One of the main merit of stratified sampling is that it helps to reduce the size of sample required to get accurate result.

false

step-by-step explanation:

false.   two legs of the trapezoid would be congruent, but the other two would not.   were all the legs congruent, then we'd have a square; were the 2 shorter sides congruent and the 2 longer sides also congruent, we'd have a rectangle.