Finding the Fourth Proportional to 12,900.39, 19,359.21 and 4,692.39

Step by Step Solution

1. Step 1: Write the proportion equation
   12,900.39 : 19,359.21 = 4,692.39 : x
2. Step 2: Convert to fraction form
   12,900.39/19,359.21 = 4,692.39/x
3. Step 3: Cross multiply
   12,900.39x = 19,359.21 × 4,692.39
4. Step 4: Simplify right side
   12,900.39x = 90,840,854.88
5. Step 5: Solve for x
   x = 90,840,854.88/12,900.39
6. Step 6: Final answer
   x = 7,041.72