Finding the Fourth Proportional to 42,002.82, 63,004.45 and 12,420.91

Step by Step Solution

1. Step 1: Write the proportion equation
   42,002.82 : 63,004.45 = 12,420.91 : x
2. Step 2: Convert to fraction form
   42,002.82/63,004.45 = 12,420.91/x
3. Step 3: Cross multiply
   42,002.82x = 63,004.45 × 12,420.91
4. Step 4: Simplify right side
   42,002.82x = 782,572,434.44
5. Step 5: Solve for x
   x = 782,572,434.44/42,002.82
6. Step 6: Final answer
   x = 18,631.43