4.5 is the answer because 
first I took out the decimal which the new number is now 13
13÷3=4R1( I divided it by 3 because 1 yard=3 feet)
 now the reminder is 1.5 which equals 18inches and 1 yard equals 36 inches
and now since 18 is 1/2 of 36 
1/2 in decimal form is 0.5 or.5
so now the answer is 4.5