Finding the Fourth Proportional to 8,956.85, 12,359.33 and 4,978.78

Step by Step Solution

1. Step 1: Write the proportion equation
   8,956.85 : 12,359.33 = 4,978.78 : x
2. Step 2: Convert to fraction form
   8,956.85/12,359.33 = 4,978.78/x
3. Step 3: Cross multiply
   8,956.85x = 12,359.33 × 4,978.78
4. Step 4: Simplify right side
   8,956.85x = 61,534,445.42
5. Step 5: Solve for x
   x = 61,534,445.42/8,956.85
6. Step 6: Final answer
   x = 6,870.10