Finding the Fourth Proportional to 22,408.56, 30,931.20 and 12,986.64

Step by Step Solution

1. Step 1: Write the proportion equation
   22,408.56 : 30,931.20 = 12,986.64 : x
2. Step 2: Convert to fraction form
   22,408.56/30,931.20 = 12,986.64/x
3. Step 3: Cross multiply
   22,408.56x = 30,931.20 × 12,986.64
4. Step 4: Simplify right side
   22,408.56x = 401,692,359.17
5. Step 5: Solve for x
   x = 401,692,359.17/22,408.56
6. Step 6: Final answer
   x = 17,925.84