Finding the Fourth Proportional to 10,980.72, 15,139.80 and 9,559.08

Step by Step Solution

1. Step 1: Write the proportion equation
   10,980.72 : 15,139.80 = 9,559.08 : x
2. Step 2: Convert to fraction form
   10,980.72/15,139.80 = 9,559.08/x
3. Step 3: Cross multiply
   10,980.72x = 15,139.80 × 9,559.08
4. Step 4: Simplify right side
   10,980.72x = 144,722,559.38
5. Step 5: Solve for x
   x = 144,722,559.38/10,980.72
6. Step 6: Final answer
   x = 13,179.70