Finding the Fourth Proportional to 138,538.79, 191,179.71 and 78,108.91

Step by Step Solution

1. Step 1: Write the proportion equation
   138,538.79 : 191,179.71 = 78,108.91 : x
2. Step 2: Convert to fraction form
   138,538.79/191,179.71 = 78,108.91/x
3. Step 3: Cross multiply
   138,538.79x = 191,179.71 × 78,108.91
4. Step 4: Simplify right side
   138,538.79x = 14,932,838,284.27
5. Step 5: Solve for x
   x = 14,932,838,284.27/138,538.79
6. Step 6: Final answer
   x = 107,788.14