Finding the Fourth Proportional to 31,069.49, 42,881.45 and 18,321.90

Step by Step Solution

1. Step 1: Write the proportion equation
   31,069.49 : 42,881.45 = 18,321.90 : x
2. Step 2: Convert to fraction form
   31,069.49/42,881.45 = 18,321.90/x
3. Step 3: Cross multiply
   31,069.49x = 42,881.45 × 18,321.90
4. Step 4: Simplify right side
   31,069.49x = 785,669,547.15
5. Step 5: Solve for x
   x = 785,669,547.15/31,069.49
6. Step 6: Final answer
   x = 25,287.50