Finding the Fourth Proportional to 13,419.56, 20,146.55 and 13,279.83

Step by Step Solution

1. Step 1: Write the proportion equation
   13,419.56 : 20,146.55 = 13,279.83 : x
2. Step 2: Convert to fraction form
   13,419.56/20,146.55 = 13,279.83/x
3. Step 3: Cross multiply
   13,419.56x = 20,146.55 × 13,279.83
4. Step 4: Simplify right side
   13,419.56x = 267,542,692.69
5. Step 5: Solve for x
   x = 267,542,692.69/13,419.56
6. Step 6: Final answer
   x = 19,936.78