Finding the Fourth Proportional to 9,178.95, 12,662.82 and 5,640.87

Step by Step Solution

1. Step 1: Write the proportion equation
   9,178.95 : 12,662.82 = 5,640.87 : x
2. Step 2: Convert to fraction form
   9,178.95/12,662.82 = 5,640.87/x
3. Step 3: Cross multiply
   9,178.95x = 12,662.82 × 5,640.87
4. Step 4: Simplify right side
   9,178.95x = 71,429,321.45
5. Step 5: Solve for x
   x = 71,429,321.45/9,178.95
6. Step 6: Final answer
   x = 7,781.86