Finding the Fourth Proportional to 9,178.96, 12,662.82 and 5,640.88

Step by Step Solution

1. Step 1: Write the proportion equation
   9,178.96 : 12,662.82 = 5,640.88 : x
2. Step 2: Convert to fraction form
   9,178.96/12,662.82 = 5,640.88/x
3. Step 3: Cross multiply
   9,178.96x = 12,662.82 × 5,640.88
4. Step 4: Simplify right side
   9,178.96x = 71,429,448.08
5. Step 5: Solve for x
   x = 71,429,448.08/9,178.96
6. Step 6: Final answer
   x = 7,781.87