Finding the Fourth Proportional to 21,990.66, 30,348.72 and 12,559.02

Step by Step Solution

1. Step 1: Write the proportion equation
   21,990.66 : 30,348.72 = 12,559.02 : x
2. Step 2: Convert to fraction form
   21,990.66/30,348.72 = 12,559.02/x
3. Step 3: Cross multiply
   21,990.66x = 30,348.72 × 12,559.02
4. Step 4: Simplify right side
   21,990.66x = 381,150,181.45
5. Step 5: Solve for x
   x = 381,150,181.45/21,990.66
6. Step 6: Final answer
   x = 17,332.37