Finding the Fourth Proportional to 12,898.71, 17,803.40 and 7,865.71

Step by Step Solution

1. Step 1: Write the proportion equation
   12,898.71 : 17,803.40 = 7,865.71 : x
2. Step 2: Convert to fraction form
   12,898.71/17,803.40 = 7,865.71/x
3. Step 3: Cross multiply
   12,898.71x = 17,803.40 × 7,865.71
4. Step 4: Simplify right side
   12,898.71x = 140,036,297.58
5. Step 5: Solve for x
   x = 140,036,297.58/12,898.71
6. Step 6: Final answer
   x = 10,856.61