Question

the scale factor of the dimensions of two similar wood floors is 5 : 4. It costs $368 to refinish the smaller wood floor.

Answer 1

smaller is 4 units

4 units=368
divide both sides by 4
1unit=92
times both sides by 5 since 5 units=big
5unit=460


costs $460 to furnnish biggger floor

Answer 2

set up a proportion 
4      368
--- =  ---- 
5        x
then cross multiply
 
368*5=4x
and divide both sides by four
92*5=x
460=x