Question 25095
A scale of 1:160 means that 1 inch on the model is equivalent to 160 inches on the real train. You can use the given scale factor in a proportion to solve this problem. It's probably easier to work in inches, so convert 45 feet to inches.
(45 ft.)(12 in.per ft.) = 540 inches.
 Now do the proportions. Let x = the length of the model engine.

{{{1/160 = x/540}}}  Multiply both sides by 540.
{{{540/160 = x}}}
{{{x = 3.375}}}inches.