Finding the Fourth Proportional to 31,017.31, 42,769.69 and 21,440.57

Step by Step Solution

1. Step 1: Write the proportion equation
   31,017.31 : 42,769.69 = 21,440.57 : x
2. Step 2: Convert to fraction form
   31,017.31/42,769.69 = 21,440.57/x
3. Step 3: Cross multiply
   31,017.31x = 42,769.69 × 21,440.57
4. Step 4: Simplify right side
   31,017.31x = 917,006,264.87
5. Step 5: Solve for x
   x = 917,006,264.87/31,017.31
6. Step 6: Final answer
   x = 29,564.34