Finding the Fourth Proportional to 13,920.57, 20,886.12 and 8,377.83

Step by Step Solution

1. Step 1: Write the proportion equation
   13,920.57 : 20,886.12 = 8,377.83 : x
2. Step 2: Convert to fraction form
   13,920.57/20,886.12 = 8,377.83/x
3. Step 3: Cross multiply
   13,920.57x = 20,886.12 × 8,377.83
4. Step 4: Simplify right side
   13,920.57x = 174,980,362.72
5. Step 5: Solve for x
   x = 174,980,362.72/13,920.57
6. Step 6: Final answer
   x = 12,569.91