Finding the Fourth Proportional to 21,903.77, 30,227.28 and 13,287.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,903.77 : 30,227.28 = 13,287.09 : x
2. Step 2: Convert to fraction form
   21,903.77/30,227.28 = 13,287.09/x
3. Step 3: Cross multiply
   21,903.77x = 30,227.28 × 13,287.09
4. Step 4: Simplify right side
   21,903.77x = 401,632,483.31
5. Step 5: Solve for x
   x = 401,632,483.31/21,903.77
6. Step 6: Final answer
   x = 18,336.23