Finding the Fourth Proportional to 12,930.34, 19,395.57 and 5,139.17

Step by Step Solution

1. Step 1: Write the proportion equation
   12,930.34 : 19,395.57 = 5,139.17 : x
2. Step 2: Convert to fraction form
   12,930.34/19,395.57 = 5,139.17/x
3. Step 3: Cross multiply
   12,930.34x = 19,395.57 × 5,139.17
4. Step 4: Simplify right side
   12,930.34x = 99,677,131.48
5. Step 5: Solve for x
   x = 99,677,131.48/12,930.34
6. Step 6: Final answer
   x = 7,708.78