Finding the Fourth Proportional to 42,472.39, 63,705.32 and 12,890.38

Step by Step Solution

1. Step 1: Write the proportion equation
   42,472.39 : 63,705.32 = 12,890.38 : x
2. Step 2: Convert to fraction form
   42,472.39/63,705.32 = 12,890.38/x
3. Step 3: Cross multiply
   42,472.39x = 63,705.32 × 12,890.38
4. Step 4: Simplify right side
   42,472.39x = 821,185,464.30
5. Step 5: Solve for x
   x = 821,185,464.30/42,472.39
6. Step 6: Final answer
   x = 19,334.57