Finding the Fourth Proportional to 12,820.87, 17,687.39 and 7,783.14

Step by Step Solution

1. Step 1: Write the proportion equation
   12,820.87 : 17,687.39 = 7,783.14 : x
2. Step 2: Convert to fraction form
   12,820.87/17,687.39 = 7,783.14/x
3. Step 3: Cross multiply
   12,820.87x = 17,687.39 × 7,783.14
4. Step 4: Simplify right side
   12,820.87x = 137,663,432.60
5. Step 5: Solve for x
   x = 137,663,432.60/12,820.87
6. Step 6: Final answer
   x = 10,737.45