Aresearcher wants to determine if preschool attendance is associated with high school graduation for low-income students. she randomly assigns low-income children to two groups; one group will attend preschool program, the second group will not attend preschool. the researcher plans to follow the children in the study for 20 years and observe whether or not they graduate from high school. which of the following is the explanatory variable in this study?
(a) the length of time it takes a subject to graduate high school
(b) the income status of the children
(c) whether or not a subject attends preschool
(d) whether or not a subject graduates high school

(C) Whether or not a subject attends preschool

Step-by-step explanation:

In research studies, variables are used to explain differences in another variable. The explanatory variable (also known as independent or predictor variable) is used to explain differences in the response variable (dependent or outcome variable).

It is important to know that the explanatory variable is the variable that is manipulated by the researcher.

The facts that are not being manipulated are the income of the children studied, and what happens after attending or not preschool program. The variable the researcher is manipulating is the assignation to groups that will or will not attend preschool. Therefore the correct answer is:

(C) Whether or not a subject attends preschool

I hope you find this information useful and interesting! Good luck!

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional