Finding the Fourth Proportional to 31,015.28, 42,812.22 and 18,440

Step by Step Solution

1. Step 1: Write the proportion equation
   31,015.28 : 42,812.22 = 18,440 : x
2. Step 2: Convert to fraction form
   31,015.28/42,812.22 = 18,440/x
3. Step 3: Cross multiply
   31,015.28x = 42,812.22 × 18,440
4. Step 4: Simplify right side
   31,015.28x = 789,457,336.80
5. Step 5: Solve for x
   x = 789,457,336.80/31,015.28
6. Step 6: Final answer
   x = 25,453.82