The table shows the amount of pet food in cups remaining in an automatic feeder as a function of the number of meals the feeder has dispensed. Write a function rule that models this situation

Numbers of Meales dispensed x:1,3,9,7
Amount of pet food remaining y: 21,15,6,3

1 answer

To create a function rule that models the relationship between the number of meals dispensed (x) and the amount of pet food remaining (y), we can analyze the provided data:

  • Number of meals dispensed (x): 1, 3, 7, 9
  • Amount of pet food remaining (y): 21, 15, 3, 6

It looks like there is a pattern between the number of meals dispensed and the amount of pet food remaining.

  1. Calculate how much pet food is dispensed per meal:

    • From the first data point, when 1 meal is dispensed, there are 21 cups remaining. The change to the second point, when 3 meals are dispensed, yields: \[ 21 - 15 = 6 \text{ cups (dispensed for 2 meals)} \] Thus, for each meal, it appears that \(\frac{6}{2} = 3\) cups are dispensed.
  2. Check consistency with other points:

    • From 3 to 7 meals: \[ y = 15 - (7 - 3) \times 3 = 15 - 12 = 3 \text{ cups remaining} \]
    • From 7 to 9 meals: \[ y = 3 - (9 - 7) \times 3 = 3 - 6 = -3 \text{ cups (not possible, which indicates an error in meal measurements)} \]

However, the value should decrease for each subsequent meal, and it appears that only valid measurements are:

  • At \( x=1 \), \( y=21 \)
  • At \( x=3 \), \( y=15 \)
  • At \( x=7 \), \( y=3 \) (as the previous calculation indicated)

Let's summarize how we can derive a linear function based on your findings with valid x-values and y-values. Notably, let's only check the points that progress logically:

  • Create a line that connects (1, 21) to (3, 15):

The slope \( m \) between these points: \[ m = \frac{15 - 21}{3 - 1} = \frac{-6}{2} = -3 \] Using point-slope form, or simply the linear equation: \[ y = mx + b \]

Using point (1, 21) to find b: \[ 21 = -3(1) + b \implies b = 24 \]

The equation at this point is: \[ y = -3x + 24 \]

We can check this with the other two points only, but assume some alteration in meal sizes with non-linear constraints due to inconsistency, but the modeling could suffice as a linear equation that may require adjustments on consumption logs to adjust for the basis of the last value.

Final concluding function: \[ y = -3x + 24 \]

With \( y \) as the amount of remaining cups and \( x \) as the number of meals dispensed. Further sampling of values should clarify whether an adjustment for dispensing behavior is necessary.