Finding the Fourth Proportional to 13,691.78, 18,894.66 and 7,404.15

Step by Step Solution

1. Step 1: Write the proportion equation
   13,691.78 : 18,894.66 = 7,404.15 : x
2. Step 2: Convert to fraction form
   13,691.78/18,894.66 = 7,404.15/x
3. Step 3: Cross multiply
   13,691.78x = 18,894.66 × 7,404.15
4. Step 4: Simplify right side
   13,691.78x = 139,898,859.82
5. Step 5: Solve for x
   x = 139,898,859.82/13,691.78
6. Step 6: Final answer
   x = 10,217.73