Finding the Fourth Proportional to 42,431.10, 63,630.45 and 12,839.10

Step by Step Solution

1. Step 1: Write the proportion equation
   42,431.10 : 63,630.45 = 12,839.10 : x
2. Step 2: Convert to fraction form
   42,431.10/63,630.45 = 12,839.10/x
3. Step 3: Cross multiply
   42,431.10x = 63,630.45 × 12,839.10
4. Step 4: Simplify right side
   42,431.10x = 816,957,710.60
5. Step 5: Solve for x
   x = 816,957,710.60/42,431.10
6. Step 6: Final answer
   x = 19,253.75