Finding the Fourth Proportional to 40,680.56, 61,021.94 and 12,978.56

Step by Step Solution

1. Step 1: Write the proportion equation
   40,680.56 : 61,021.94 = 12,978.56 : x
2. Step 2: Convert to fraction form
   40,680.56/61,021.94 = 12,978.56/x
3. Step 3: Cross multiply
   40,680.56x = 61,021.94 × 12,978.56
4. Step 4: Simplify right side
   40,680.56x = 791,976,997.27
5. Step 5: Solve for x
   x = 791,976,997.27/40,680.56
6. Step 6: Final answer
   x = 19,468.19