Finding the Fourth Proportional to 1,560.52, 2,153.51 and 861.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,560.52 : 2,153.51 = 861.89 : x
2. Step 2: Convert to fraction form
   1,560.52/2,153.51 = 861.89/x
3. Step 3: Cross multiply
   1,560.52x = 2,153.51 × 861.89
4. Step 4: Simplify right side
   1,560.52x = 1,856,088.73
5. Step 5: Solve for x
   x = 1,856,088.73/1,560.52
6. Step 6: Final answer
   x = 1,189.40