Finding the Fourth Proportional to 40,978.77, 61,470.63 and 12,899.74

Step by Step Solution

1. Step 1: Write the proportion equation
   40,978.77 : 61,470.63 = 12,899.74 : x
2. Step 2: Convert to fraction form
   40,978.77/61,470.63 = 12,899.74/x
3. Step 3: Cross multiply
   40,978.77x = 61,470.63 × 12,899.74
4. Step 4: Simplify right side
   40,978.77x = 792,955,144.64
5. Step 5: Solve for x
   x = 792,955,144.64/40,978.77
6. Step 6: Final answer
   x = 19,350.39