Finding the Fourth Proportional to 42,002.34, 63,004.31 and 12,420.12

Step by Step Solution

1. Step 1: Write the proportion equation
   42,002.34 : 63,004.31 = 12,420.12 : x
2. Step 2: Convert to fraction form
   42,002.34/63,004.31 = 12,420.12/x
3. Step 3: Cross multiply
   42,002.34x = 63,004.31 × 12,420.12
4. Step 4: Simplify right side
   42,002.34x = 782,521,090.72
5. Step 5: Solve for x
   x = 782,521,090.72/42,002.34
6. Step 6: Final answer
   x = 18,630.42