Finding the Fourth Proportional to 1,108.31, 1,661.82 and 560.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,108.31 : 1,661.82 = 560.21 : x
2. Step 2: Convert to fraction form
   1,108.31/1,661.82 = 560.21/x
3. Step 3: Cross multiply
   1,108.31x = 1,661.82 × 560.21
4. Step 4: Simplify right side
   1,108.31x = 930,968.18
5. Step 5: Solve for x
   x = 930,968.18/1,108.31
6. Step 6: Final answer
   x = 839.99