Y=8*(1/3)x
Exponential decay or Exponential growth ​

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constant of proportionality = 3 and the equation is c = 3p.

step-by-step explanation:

c = kp   where c = amount of caffeine in mg., p = oz of pepsi and k is the constant of proportionality.

substituting the values given:

24 = 8k

k = 3.

the same value of k will be obtained if we substitute the other given values.

x:       y:  

-1         4

0         4

1         6

2         18

3         20