Finding the Fourth Proportional to 13,692.72, 18,895.92 and 7,405.20

Step by Step Solution

1. Step 1: Write the proportion equation
   13,692.72 : 18,895.92 = 7,405.20 : x
2. Step 2: Convert to fraction form
   13,692.72/18,895.92 = 7,405.20/x
3. Step 3: Cross multiply
   13,692.72x = 18,895.92 × 7,405.20
4. Step 4: Simplify right side
   13,692.72x = 139,928,066.78
5. Step 5: Solve for x
   x = 139,928,066.78/13,692.72
6. Step 6: Final answer
   x = 10,219.16