Finding the Fourth Proportional to 21,990.56, 30,347.92 and 12,559.84

Step by Step Solution

1. Step 1: Write the proportion equation
   21,990.56 : 30,347.92 = 12,559.84 : x
2. Step 2: Convert to fraction form
   21,990.56/30,347.92 = 12,559.84/x
3. Step 3: Cross multiply
   21,990.56x = 30,347.92 × 12,559.84
4. Step 4: Simplify right side
   21,990.56x = 381,165,019.53
5. Step 5: Solve for x
   x = 381,165,019.53/21,990.56
6. Step 6: Final answer
   x = 17,333.12