Finding the Fourth Proportional to 1,130.72, 1,560.56 and 665.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,130.72 : 1,560.56 = 665.12 : x
2. Step 2: Convert to fraction form
   1,130.72/1,560.56 = 665.12/x
3. Step 3: Cross multiply
   1,130.72x = 1,560.56 × 665.12
4. Step 4: Simplify right side
   1,130.72x = 1,037,959.67
5. Step 5: Solve for x
   x = 1,037,959.67/1,130.72
6. Step 6: Final answer
   x = 917.96