Finding the Fourth Proportional to 1,081.31, 1,618.99 and 560.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.31 : 1,618.99 = 560.21 : x
2. Step 2: Convert to fraction form
   1,081.31/1,618.99 = 560.21/x
3. Step 3: Cross multiply
   1,081.31x = 1,618.99 × 560.21
4. Step 4: Simplify right side
   1,081.31x = 906,964.89
5. Step 5: Solve for x
   x = 906,964.89/1,081.31
6. Step 6: Final answer
   x = 838.77