We are given that:
[tex]\begin{gathered} C=67^{\circ}, \\ k=0.073354. \end{gathered}[/tex]
We know that, at t=0,
[tex]T=148^{\circ}=Ae^0+C,[/tex]
solving the above equation for A, we get:
[tex]A=148^{\circ}-67^{\circ}=81^{\circ}.[/tex]
Now, setting T=102°, we get:
[tex]102^{\circ}=81^{\circ}e^{-kt}+67^{\circ}.[/tex]
Solving the above equation for t, we get:
[tex]\begin{gathered} 102^{\circ}-67^{\circ}=81^{\circ}e^{-0.073354t}, \\ 35^{\circ}=81^{\circ}e^{-0.073354t}, \\ e^{-0.073354t}=\frac{35}{81}, \\ -0.073354t=ln(\frac{35}{81}), \\ t=\frac{ln(\frac{35}{81})}{-0.073354}. \end{gathered}[/tex]
Finally, we get:
[tex]t\approx11.44.[/tex]
Answer:
[tex]11.44[/tex]