Question

to study the amount of time spend on homework each day, a sample containing 100 freshmen, 100 sophomores, 100 juniors, and 100 seniors are selected. convenience sample simple random sample systematic sample stratified sample what is a stratified sample? all members of the population have an equal chance of selection a population is divided into groups and members of the sample are randomly selected from each group. a population is divided into groups and only some of the groups are chosen for the sample each member of the population is assigned a number and every n th member is chosen for the sample

Explanation:

In the first part, the sample is divided by class - freshmen, sophomores, juniors, and seniors, and a fixed number from each group is selected, which is characteristic of a stratified sample. For the second part, by definition, in a stratified sample, a population is divided into groups (strata) and members of the sample are randomly selected from each group.

Answer:

First question: Stratified Sample
Second question: A population is divided into groups and members of the sample are randomly selected from each group.