Answer:4800'
Explanation:
It is 4800' because x = the number of seconds between the lightning and thunder and 1,200 is in feet. so, if there is four seconds between the time of the lightning and thunder then you can use the equation given f(x) or 1,200(x) to solve it. to do this you supplement the x with 4 which gives you 1,200(4) or the same as 1,200 · 4 = 4800ft.