Finding the Fourth Proportional to 1,108.80, 1,530.16 and 666.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,108.80 : 1,530.16 = 666.72 : x
2. Step 2: Convert to fraction form
   1,108.80/1,530.16 = 666.72/x
3. Step 3: Cross multiply
   1,108.80x = 1,530.16 × 666.72
4. Step 4: Simplify right side
   1,108.80x = 1,020,188.28
5. Step 5: Solve for x
   x = 1,020,188.28/1,108.80
6. Step 6: Final answer
   x = 920.08