Finding the Fourth Proportional to 138,069, 206,771.35 and 78,724.76

Step by Step Solution

1. Step 1: Write the proportion equation
   138,069 : 206,771.35 = 78,724.76 : x
2. Step 2: Convert to fraction form
   138,069/206,771.35 = 78,724.76/x
3. Step 3: Cross multiply
   138,069x = 206,771.35 × 78,724.76
4. Step 4: Simplify right side
   138,069x = 16,278,023,476.15
5. Step 5: Solve for x
   x = 16,278,023,476.15/138,069
6. Step 6: Final answer
   x = 117,897.74