Answer:
Proportionality constant =
Step-by-step explanation:
From the graph attached,
Data set representing the relation between seeing lightning and the hearing thunder is,
{(15, 3), (25, 5), (35, 7), (45, 9)}
Since, Distance from lightening (d) ∝ Time between lightening and thunder (t)
d = kt
Here k = proportionality constant
k =
From the data set one point is (15, 3).
k =
k = miles per second
Therefore, proportionality constant is miles per second.