Finding the Fourth Proportional to 139,976.61, 210,051.99 and 56,870.61

Step by Step Solution

1. Step 1: Write the proportion equation
   139,976.61 : 210,051.99 = 56,870.61 : x
2. Step 2: Convert to fraction form
   139,976.61/210,051.99 = 56,870.61/x
3. Step 3: Cross multiply
   139,976.61x = 210,051.99 × 56,870.61
4. Step 4: Simplify right side
   139,976.61x = 11,945,784,803.01
5. Step 5: Solve for x
   x = 11,945,784,803.01/139,976.61
6. Step 6: Final answer
   x = 85,341.29