Finding the Fourth Proportional to 139,964.71, 193,145.55 and 78,709.15

Step by Step Solution

1. Step 1: Write the proportion equation
   139,964.71 : 193,145.55 = 78,709.15 : x
2. Step 2: Convert to fraction form
   139,964.71/193,145.55 = 78,709.15/x
3. Step 3: Cross multiply
   139,964.71x = 193,145.55 × 78,709.15
4. Step 4: Simplify right side
   139,964.71x = 15,202,321,583.92
5. Step 5: Solve for x
   x = 15,202,321,583.92/139,964.71
6. Step 6: Final answer
   x = 108,615.39