Finding the Fourth Proportional to 7,705.72, 10,644.78 and 6,131.80

Step by Step Solution

1. Step 1: Write the proportion equation
   7,705.72 : 10,644.78 = 6,131.80 : x
2. Step 2: Convert to fraction form
   7,705.72/10,644.78 = 6,131.80/x
3. Step 3: Cross multiply
   7,705.72x = 10,644.78 × 6,131.80
4. Step 4: Simplify right side
   7,705.72x = 65,271,662.00
5. Step 5: Solve for x
   x = 65,271,662.00/7,705.72
6. Step 6: Final answer
   x = 8,470.55