Finding the Fourth Proportional to 13,689.61, 18,891.66 and 7,401.98

Step by Step Solution

1. Step 1: Write the proportion equation
   13,689.61 : 18,891.66 = 7,401.98 : x
2. Step 2: Convert to fraction form
   13,689.61/18,891.66 = 7,401.98/x
3. Step 3: Cross multiply
   13,689.61x = 18,891.66 × 7,401.98
4. Step 4: Simplify right side
   13,689.61x = 139,835,764.47
5. Step 5: Solve for x
   x = 139,835,764.47/13,689.61
6. Step 6: Final answer
   x = 10,214.74