Finding the Fourth Proportional to 21,991.52, 30,345 and 12,558.08

Step by Step Solution

1. Step 1: Write the proportion equation
   21,991.52 : 30,345 = 12,558.08 : x
2. Step 2: Convert to fraction form
   21,991.52/30,345 = 12,558.08/x
3. Step 3: Cross multiply
   21,991.52x = 30,345 × 12,558.08
4. Step 4: Simplify right side
   21,991.52x = 381,074,937.60
5. Step 5: Solve for x
   x = 381,074,937.60/21,991.52
6. Step 6: Final answer
   x = 17,328.27