Finding the Fourth Proportional to 139,128.09, 191,996.78 and 78,697.44

Step by Step Solution

1. Step 1: Write the proportion equation
   139,128.09 : 191,996.78 = 78,697.44 : x
2. Step 2: Convert to fraction form
   139,128.09/191,996.78 = 78,697.44/x
3. Step 3: Cross multiply
   139,128.09x = 191,996.78 × 78,697.44
4. Step 4: Simplify right side
   139,128.09x = 15,109,654,680.76
5. Step 5: Solve for x
   x = 15,109,654,680.76/139,128.09
6. Step 6: Final answer
   x = 108,602.47