Negative Slope This activity will help you meet these educational goals: Mathematical Practices—You will make sense of problems and solve them, reason abstractly and quantitatively, use mathematics to model real-world situations, attend to precision, and look for and make use of structure. Directions Read the instructions for this self-checked activity. Type in your response to each question, and check your answers. At the end of the activity, write a brief evaluation of your work. Activity A submarine is at a depth of 100 feet below sea level. Then it starts to dive at a rate of 50 feet per minute. Use this information to answer the following questions. Question 1 Part A For this situation, what is the independent variable (include units)?