Finding the Fourth Proportional to 12,078.21, 18,123.50 and 5,503.55

Step by Step Solution

1. Step 1: Write the proportion equation
   12,078.21 : 18,123.50 = 5,503.55 : x
2. Step 2: Convert to fraction form
   12,078.21/18,123.50 = 5,503.55/x
3. Step 3: Cross multiply
   12,078.21x = 18,123.50 × 5,503.55
4. Step 4: Simplify right side
   12,078.21x = 99,743,480.61
5. Step 5: Solve for x
   x = 99,743,480.61/12,078.21
6. Step 6: Final answer
   x = 8,258.13