Question

greta and greg are twins. their parents want to know if watching television helps or harms language development. they design a long-term experiment in which greta watches twice as much television as greg every day.

which statement is true of this experiment?

a.) the twins language development and the amount of television that each twin watches are both explanatory variables.

b.) the twins language development is the response variable.

c.) the amount of television that each twin watches is the response variable.

d.) the twins language development is the explanatory variable.

Explanation:

Identify the variables in the study

The parents want to study the effect of watching television on language development.
The amount of television watched is manipulated or set by the parents (Greta watches twice as much as Greg).
Language development is the outcome being measured to see if it is affected.

Define explanatory and response variables

An explanatory variable (independent variable) is the factor manipulated or controlled to observe its effect.
A response variable (dependent variable) is the outcome measured to see how it responds to changes in the explanatory variable.

Classify the variables in this experiment

The explanatory variable is the amount of television watched.
The response variable is the twins' language development.

Evaluate the given choices

• Choice (a) states both are explanatory variables, which is incorrect.
• Choice (b) states language development is the response variable, which is correct.
• Choice (c) states television amount is the response variable, which is incorrect.
• Choice (d) states language development is the explanatory variable, which is incorrect.

Answer:

• a.) The twin's language development and the amount of television that each twin watches are both explanatory variables.
• b.) The twins' language development is the response variable. (Correct answer)
• c.) The amount of television that each twin watches is the response variable.
• d.) The twins' language development is the explanatory variable.