Answer:
The function for Bruce’s elevation is
and because b=6 that is greater than 0, it is an exponential growth function.
Explanation:
We have given initial Bruce’s elevation = 1,505 feet.
We know, the exponential function
, where a is the initial value, b is the growth factor and x is the exponent represents time in hours.
Each successive hour, his average elevation change for the hike becomes 6 times the previous hourly elevation change.
Therefore, initial value a=1505, growth factor b for exponential function
is 6.
Now we can plug a=1505 and b=6 in
, we get

Also note, if b>0, it would be an exponential growth function.
Therefore, the function for Bruce’s elevation is
and because b=6 that is greater than 0, it is an exponential growth function.