Finding the Fourth Proportional to 139,681.43, 192,780.69 and 78,434.49

Step by Step Solution

1. Step 1: Write the proportion equation
   139,681.43 : 192,780.69 = 78,434.49 : x
2. Step 2: Convert to fraction form
   139,681.43/192,780.69 = 78,434.49/x
3. Step 3: Cross multiply
   139,681.43x = 192,780.69 × 78,434.49
4. Step 4: Simplify right side
   139,681.43x = 15,120,655,971.99
5. Step 5: Solve for x
   x = 15,120,655,971.99/139,681.43
6. Step 6: Final answer
   x = 108,251.01