Answer:
The reasonable value for the variable r is 593.
Explanation:
Here variable r represents the total amount of rain for the other 19 years,
⇒ The total rain in 20 years = r + rain in this year
Given,
Rain in this year = 28 inches,
⇒ Total rain in 20 years = ( r + 28 ) inches
According to the question,
Total rain in 20 years = 621 inches,
r + 28 = 621
Subtracting 28 on both sides,
We get,
r = 621 - 28 = 593 inches,
Hence, the reasonable value for the variable r is 593.