Finding the Fourth Proportional to 8,051.25, 11,105.11 and 7,780.31

Step by Step Solution

1. Step 1: Write the proportion equation
   8,051.25 : 11,105.11 = 7,780.31 : x
2. Step 2: Convert to fraction form
   8,051.25/11,105.11 = 7,780.31/x
3. Step 3: Cross multiply
   8,051.25x = 11,105.11 × 7,780.31
4. Step 4: Simplify right side
   8,051.25x = 86,401,172.35
5. Step 5: Solve for x
   x = 86,401,172.35/8,051.25
6. Step 6: Final answer
   x = 10,731.39