Finding the Fourth Proportional to 42,634.05, 63,940.17 and 12,641.28

Step by Step Solution

1. Step 1: Write the proportion equation
   42,634.05 : 63,940.17 = 12,641.28 : x
2. Step 2: Convert to fraction form
   42,634.05/63,940.17 = 12,641.28/x
3. Step 3: Cross multiply
   42,634.05x = 63,940.17 × 12,641.28
4. Step 4: Simplify right side
   42,634.05x = 808,285,592.22
5. Step 5: Solve for x
   x = 808,285,592.22/42,634.05
6. Step 6: Final answer
   x = 18,958.69