Finding the Fourth Proportional to 1,512.10, 2,086.05 and 1,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,512.10 : 2,086.05 = 1,139.50 : x
2. Step 2: Convert to fraction form
   1,512.10/2,086.05 = 1,139.50/x
3. Step 3: Cross multiply
   1,512.10x = 2,086.05 × 1,139.50
4. Step 4: Simplify right side
   1,512.10x = 2,377,053.98
5. Step 5: Solve for x
   x = 2,377,053.98/1,512.10
6. Step 6: Final answer
   x = 1,572.02