Finding the Fourth Proportional to 42,469.86, 63,707.79 and 12,890.10

Step by Step Solution

1. Step 1: Write the proportion equation
   42,469.86 : 63,707.79 = 12,890.10 : x
2. Step 2: Convert to fraction form
   42,469.86/63,707.79 = 12,890.10/x
3. Step 3: Cross multiply
   42,469.86x = 63,707.79 × 12,890.10
4. Step 4: Simplify right side
   42,469.86x = 821,199,783.88
5. Step 5: Solve for x
   x = 821,199,783.88/42,469.86
6. Step 6: Final answer
   x = 19,336.06