Finding the Fourth Proportional to 13,256.77, 19,872.78 and 4,485.55

Step by Step Solution

1. Step 1: Write the proportion equation
   13,256.77 : 19,872.78 = 4,485.55 : x
2. Step 2: Convert to fraction form
   13,256.77/19,872.78 = 4,485.55/x
3. Step 3: Cross multiply
   13,256.77x = 19,872.78 × 4,485.55
4. Step 4: Simplify right side
   13,256.77x = 89,140,348.33
5. Step 5: Solve for x
   x = 89,140,348.33/13,256.77
6. Step 6: Final answer
   x = 6,724.14