Which of the following situations involves an external attribution? A. Desiree believes she did well on the exam because she is intelligent.
B. Thomas believes he did well on the exam because he knows a lot about math.
C. Nick believes he did well on the exam because the exam was easy.
D. Cassidy believes she did well on the exam because she tried very hard.

 C. Nick believes he did well on the exam because the exam was easy.

 

Explanation:

Nick is relating his performance on the exam to an external factor (the difficulty of the exam being easy).

All the other answers are relating the exam to internal factors such as intelligence, personal knowledge, and effort.

(a) is the correct option

Explanation:

Yield of tomatoes is a dependent variable

The dependent variable is something that is observable and measurable, here in this case yield of tomatoes can be calculated and measured depending on the type or concentration of fertilizer usedThe independent variable, also known as the experimental treatment is the difference or change in the experimental conditions that is chosen, here in this case it is the concentration or type of fertilizerTo ensure that only the independent variable is affecting the dependent variable, all the other factors acting upon the test situation must be kept constant, these factors that must be kept the same are called the controlled variables, or constant variablesHere in this case amount of water, exposure to sunlight and type of seedlings is kept same