Finding the Fourth Proportional to 20,388.33, 30,561.83 and 13,815.18

Step by Step Solution

1. Step 1: Write the proportion equation
   20,388.33 : 30,561.83 = 13,815.18 : x
2. Step 2: Convert to fraction form
   20,388.33/30,561.83 = 13,815.18/x
3. Step 3: Cross multiply
   20,388.33x = 30,561.83 × 13,815.18
4. Step 4: Simplify right side
   20,388.33x = 422,217,064.31
5. Step 5: Solve for x
   x = 422,217,064.31/20,388.33
6. Step 6: Final answer
   x = 20,708.77