Finding the Fourth Proportional to 139,978.58, 210,055.35 and 56,872.58

Step by Step Solution

1. Step 1: Write the proportion equation
   139,978.58 : 210,055.35 = 56,872.58 : x
2. Step 2: Convert to fraction form
   139,978.58/210,055.35 = 56,872.58/x
3. Step 3: Cross multiply
   139,978.58x = 210,055.35 × 56,872.58
4. Step 4: Simplify right side
   139,978.58x = 11,946,389,697.30
5. Step 5: Solve for x
   x = 11,946,389,697.30/139,978.58
6. Step 6: Final answer
   x = 85,344.41