Question 1116711
98.6=70+c*e^0
c=28.6  ANSWER
90=70+28.6*e^kt
88.5=70+28.6e^k(t+1)
From the first:
0.6993=e^kt
ln both sides
kt=-0.3577
From the second:
18.5=28.6*(e^kt)*e^k
0.6469=e^k(t+1)
ln both sides
-0.4356=k(t+1)=kt + k
-0.4356+0.3577=-0.0779=k, by substitution  ANSWER
kt=-0.3577
-0.0779*t=-0.3577
t=4.59 hours earlier than 11 pm or 6.41 hours time or 6:25 pm to the nearest minute ANSWER
check
t(4.59)=70+28.6*e*(4.59*(-0.0779)
=70+20=90
at 5.59 hours
t(5.59=70+28.6(e^(5.59*(-0.0779))=88.5