Finding the Fourth Proportional to 8,780.32, 12,118.16 and 5,245.60

Step by Step Solution

1. Step 1: Write the proportion equation
   8,780.32 : 12,118.16 = 5,245.60 : x
2. Step 2: Convert to fraction form
   8,780.32/12,118.16 = 5,245.60/x
3. Step 3: Cross multiply
   8,780.32x = 12,118.16 × 5,245.60
4. Step 4: Simplify right side
   8,780.32x = 63,567,020.10
5. Step 5: Solve for x
   x = 63,567,020.10/8,780.32
6. Step 6: Final answer
   x = 7,239.72