Finding the Fourth Proportional to 31,127.44, 42,969.78 and 21,086.37

Step by Step Solution

1. Step 1: Write the proportion equation
   31,127.44 : 42,969.78 = 21,086.37 : x
2. Step 2: Convert to fraction form
   31,127.44/42,969.78 = 21,086.37/x
3. Step 3: Cross multiply
   31,127.44x = 42,969.78 × 21,086.37
4. Step 4: Simplify right side
   31,127.44x = 906,076,574.47
5. Step 5: Solve for x
   x = 906,076,574.47/31,127.44
6. Step 6: Final answer
   x = 29,108.62