Answer:

Step-by-step explanation:
The given function is f(x)=x.
If we stretch vertically by a factor of 4 and a translation of 4 units up then the new function becomes

But f(x)=x
We substitute to obtain the equation of g(x) as

Look at the problem and do it in order
6 / 21.6 = 1 / x
cross multiply
6x = 21.6
x = 21.6/6
x = 3.6
so ur answer is A : 1 in : 3.6 ft