Question

lisa is studying. the number of minutes she has studied varies directly with the number of calories she has burned. see the graph below.
(a) how many calories is lisa burning per minute?
square calorie(s)
(b) what is the slope of the graph?
square

Explanation:

Step1: Identify direct variation points

From the graph, when minutes $m=20$, calories $c=80$.

Step2: Calculate calories per minute

Calories per minute = $\frac{\text{Calories}}{\text{Minutes}}$
$\frac{80}{20}=4$

Step3: Define slope for direct variation

Slope = $\frac{\text{Change in } y}{\text{Change in } x}$, where $y$=minutes, $x$=calories.

Step4: Compute the slope

Slope = $\frac{20}{80}=\frac{1}{4}$

Answer:

(a) 4 calorie(s)
(b) $\frac{1}{4}$