Finding the Fourth Proportional to 42,271.71, 63,418.10 and 12,690.09

Step by Step Solution

1. Step 1: Write the proportion equation
   42,271.71 : 63,418.10 = 12,690.09 : x
2. Step 2: Convert to fraction form
   42,271.71/63,418.10 = 12,690.09/x
3. Step 3: Cross multiply
   42,271.71x = 63,418.10 × 12,690.09
4. Step 4: Simplify right side
   42,271.71x = 804,781,333.18
5. Step 5: Solve for x
   x = 804,781,333.18/42,271.71
6. Step 6: Final answer
   x = 19,038.30