Finding the Fourth Proportional to 31,123.31, 42,936.48 and 21,048.03

Step by Step Solution

1. Step 1: Write the proportion equation
   31,123.31 : 42,936.48 = 21,048.03 : x
2. Step 2: Convert to fraction form
   31,123.31/42,936.48 = 21,048.03/x
3. Step 3: Cross multiply
   31,123.31x = 42,936.48 × 21,048.03
4. Step 4: Simplify right side
   31,123.31x = 903,728,319.13
5. Step 5: Solve for x
   x = 903,728,319.13/31,123.31
6. Step 6: Final answer
   x = 29,037.03