Finding the Fourth Proportional to 13,689.10, 18,890.90 and 7,401.48

Step by Step Solution

1. Step 1: Write the proportion equation
   13,689.10 : 18,890.90 = 7,401.48 : x
2. Step 2: Convert to fraction form
   13,689.10/18,890.90 = 7,401.48/x
3. Step 3: Cross multiply
   13,689.10x = 18,890.90 × 7,401.48
4. Step 4: Simplify right side
   13,689.10x = 139,820,618.53
5. Step 5: Solve for x
   x = 139,820,618.53/13,689.10
6. Step 6: Final answer
   x = 10,214.01