Finding the Fourth Proportional to 10,651.16, 15,979.58 and 8,780.47

Step by Step Solution

1. Step 1: Write the proportion equation
   10,651.16 : 15,979.58 = 8,780.47 : x
2. Step 2: Convert to fraction form
   10,651.16/15,979.58 = 8,780.47/x
3. Step 3: Cross multiply
   10,651.16x = 15,979.58 × 8,780.47
4. Step 4: Simplify right side
   10,651.16x = 140,308,222.80
5. Step 5: Solve for x
   x = 140,308,222.80/10,651.16
6. Step 6: Final answer
   x = 13,173.05