Finding the Fourth Proportional to 20,408.22, 28,171.98 and 12,453.30

Step by Step Solution

1. Step 1: Write the proportion equation
   20,408.22 : 28,171.98 = 12,453.30 : x
2. Step 2: Convert to fraction form
   20,408.22/28,171.98 = 12,453.30/x
3. Step 3: Cross multiply
   20,408.22x = 28,171.98 × 12,453.30
4. Step 4: Simplify right side
   20,408.22x = 350,834,118.53
5. Step 5: Solve for x
   x = 350,834,118.53/20,408.22
6. Step 6: Final answer
   x = 17,190.82