Answer:
[tex]\frac{\Delta T}{\Delta t} = -15\,\frac{^{\textdegree}C}{min}[/tex]
Step-by-step explanation:
The average change in temperature is:
[tex]\frac{\Delta T}{\Delta t} = \frac{19\,^{\textdegree}C-100\,^{\textdegree}C}{\frac{27}{5}\,min }[/tex]
[tex]\frac{\Delta T}{\Delta t} = -15\,\frac{^{\textdegree}C}{min}[/tex]