Researchers tracked 2668 people from early childhood through adulthood and found that 13-year-olds who are frequent targets of bullies were three times more likely than their non-victimized peers to be depressed later as adults.

Identify the population, sample, and variables for the study.

Step-by-step explanation:

(A) The population is the 2,668 people who were tracked from early childhood to adulthood.

(B) The sample comprised all 13-year olds within the population. Since the members of the population started out as kids (and later became adults), the sample was inclusive of all 2,668 individuals but only at the age of 13. That is where the focus was; at the age of 13.

The study then proceeded to divide them into two groups - the experimental group (13 year olds who were frequent targets of bullies) and the non-experimental group (13 year olds who were not frequent targets of bullies).

(C) The variables in this study are:

- 13 year olds who were frequent targets of bullies

- 13 year olds who were not frequent targets of bullies

- Adults (from the same population who were once 13 year olds) with depression

- Adults (from the same population who were once 13 year olds) without depression.

NOTE HOWEVER that the degree of bullying each teenager faced and the magnitude of depression each adult faced, can be gotten from the above variables; when they assume a figure or number which can be high, low or medium.

step-by-step explanation: