Finding the Fourth Proportional to 42,731.31, 64,103.04 and 13,151.61

Step by Step Solution

1. Step 1: Write the proportion equation
   42,731.31 : 64,103.04 = 13,151.61 : x
2. Step 2: Convert to fraction form
   42,731.31/64,103.04 = 13,151.61/x
3. Step 3: Cross multiply
   42,731.31x = 64,103.04 × 13,151.61
4. Step 4: Simplify right side
   42,731.31x = 843,058,181.89
5. Step 5: Solve for x
   x = 843,058,181.89/42,731.31
6. Step 6: Final answer
   x = 19,729.28