Question

The 'Check Engine' light comes on in a car, and a mechanic discovers that the catalytic converter isn't working.

1. What is the independent variable?

a. the catalytic converter b. the mechanic c. the 'Check engine' light

2. What is the dependent variable?

a. the catalytic converter b. the mechanic c. the 'Check engine' light

A dentist wants to know whether posters of calming nature scenes will reduce patient anxiety.

3. Which of these is the most important Confounding variable in this experiment?

a. the age of the patient b. a reduction in anxiety c. how crowded the waiting room becomes d. both a and c

A gardener wants to know whether scarecrows will keep birds away from his fruit trees.

4. Which of these is the most important Confounding variable in this experiment?

a. the time of year b. the use of a scarecrow c. the amount of fruit eaten by birds d.the amount of ripe fruit in the trees

Answer 1

In an experiment or event, there is a dependent variable and an independent variable. Dependent variable is a outcome which depends on the input from independent variable.

In the given case, "Check engine light' is dependent on the working of catalytic converter. Hence, catalytic converter is an independent variable whereas " Check engine " light is a dependent variable.

Answers 1:

Independent variable- (a) the catalytic converter.

Answer 2:

Dependent variable-(C) the 'Check engine' light.

Answer 3:

Confounding variables are those external factors which affect the results of a study. Age and crowdness are confounding variables in the dentist case. In case of Scarecrow, time of the year is a confounding factor.

Confounding variables- (d) both a and c.

​​​​​​Answer 4:

(a) time of the year.