Finding the Fourth Proportional to 12,912.61, 17,819.99 and 10,113.25

Step by Step Solution

1. Step 1: Write the proportion equation
   12,912.61 : 17,819.99 = 10,113.25 : x
2. Step 2: Convert to fraction form
   12,912.61/17,819.99 = 10,113.25/x
3. Step 3: Cross multiply
   12,912.61x = 17,819.99 × 10,113.25
4. Step 4: Simplify right side
   12,912.61x = 180,218,013.87
5. Step 5: Solve for x
   x = 180,218,013.87/12,912.61
6. Step 6: Final answer
   x = 13,956.75