Finding the Fourth Proportional to 42,687.48, 64,040.74 and 13,108.31

Step by Step Solution

1. Step 1: Write the proportion equation
   42,687.48 : 64,040.74 = 13,108.31 : x
2. Step 2: Convert to fraction form
   42,687.48/64,040.74 = 13,108.31/x
3. Step 3: Cross multiply
   42,687.48x = 64,040.74 × 13,108.31
4. Step 4: Simplify right side
   42,687.48x = 839,465,519.57
5. Step 5: Solve for x
   x = 839,465,519.57/42,687.48
6. Step 6: Final answer
   x = 19,665.38