The average = Total temperature / Number of days
Since the number of days = 5
Since the temperature dropped a total of 50 degrees
So the average is
[tex]\begin{gathered} \text{ave}\mathrm{}=\frac{50}{5} \\ \text{ave}\mathrm{}=\text{ 10 degrees/day} \end{gathered}[/tex]The answer is: the average change in temperature is 10 degrees per day