Answer: The function can be represented by the exponential function :

This function has no x-intercept
.
After 7.86 years the value of the investment will be 3 times the initial value .
After 8 years the value of the investment will be $184.00.
Step-by-step explanation:
The exponential growth function is given by :-
, where A is the initial value , r is the rate of growth and x is the time period.
Given: A = $60
r=15%=0.15
Now, the function can be represented by the exponential function :

We know that exponential function has no intercept , thus this function has no intercept.
∴
Now, at x=4

Now, at x=6

Now, at x=7.86

∴ After 7.86 years the value of the investment will be 3 times the initial value
Now, at x=8
