Finding the Fourth Proportional to 21,086.78, 31,618.55 and 7,039.41

Step by Step Solution

1. Step 1: Write the proportion equation
   21,086.78 : 31,618.55 = 7,039.41 : x
2. Step 2: Convert to fraction form
   21,086.78/31,618.55 = 7,039.41/x
3. Step 3: Cross multiply
   21,086.78x = 31,618.55 × 7,039.41
4. Step 4: Simplify right side
   21,086.78x = 222,575,836.08
5. Step 5: Solve for x
   x = 222,575,836.08/21,086.78
6. Step 6: Final answer
   x = 10,555.23