Finding the Fourth Proportional to 1,560.72, 2,153.80 and 862.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,560.72 : 2,153.80 = 862.10 : x
2. Step 2: Convert to fraction form
   1,560.72/2,153.80 = 862.10/x
3. Step 3: Cross multiply
   1,560.72x = 2,153.80 × 862.10
4. Step 4: Simplify right side
   1,560.72x = 1,856,790.98
5. Step 5: Solve for x
   x = 1,856,790.98/1,560.72
6. Step 6: Final answer
   x = 1,189.70