Finding the Fourth Proportional to 12,780.82, 17,636.52 and 7,115.14

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780.82 : 17,636.52 = 7,115.14 : x
2. Step 2: Convert to fraction form
   12,780.82/17,636.52 = 7,115.14/x
3. Step 3: Cross multiply
   12,780.82x = 17,636.52 × 7,115.14
4. Step 4: Simplify right side
   12,780.82x = 125,486,308.91
5. Step 5: Solve for x
   x = 125,486,308.91/12,780.82
6. Step 6: Final answer
   x = 9,818.33