Finding the Fourth Proportional to 42,421.40, 63,633 and 12,839.18

Step by Step Solution

1. Step 1: Write the proportion equation
   42,421.40 : 63,633 = 12,839.18 : x
2. Step 2: Convert to fraction form
   42,421.40/63,633 = 12,839.18/x
3. Step 3: Cross multiply
   42,421.40x = 63,633 × 12,839.18
4. Step 4: Simplify right side
   42,421.40x = 816,995,540.94
5. Step 5: Solve for x
   x = 816,995,540.94/42,421.40
6. Step 6: Final answer
   x = 19,259.04