<PRE><B>Question 251260</B>
This problem is not quite defined enough so I have to give you 2 answers.

(1)
if the exponential (t) = temp. then:

15 = A(t)  so:

15 = 10e^.0095(t)  divide both sides by 10
1.5 = e^.0095(t)  e is the inverse natural log (ln) of 1 so take the natural 
                  of both sides... that is usually (ln) on your calculator
ln (1.5) = ln (e^.0095(t)
.40546 = .0095(t)   by taking the ln of e brings the exponential down..(I am sorry that I do not remember the exact proof)

now divide both sides by .0095

42.68 = t  so the temperature is 42.68 degrees Celcius

(2)
if the exponential (t) = 15 then

A(t) = 10e^.0095(15)
A(t) = 10e^0.1425
A(t) = 10(1.15315)  use the e^x key on your calculator..on mine it is a second
                    function
A(t) = 11.5 degrees Celcius

I hope this helps</PRE>