Finding the Fourth Proportional to 9,178.56, 12,654.63 and 7,917.16

Step by Step Solution

1. Step 1: Write the proportion equation
   9,178.56 : 12,654.63 = 7,917.16 : x
2. Step 2: Convert to fraction form
   9,178.56/12,654.63 = 7,917.16/x
3. Step 3: Cross multiply
   9,178.56x = 12,654.63 × 7,917.16
4. Step 4: Simplify right side
   9,178.56x = 100,188,730.45
5. Step 5: Solve for x
   x = 100,188,730.45/9,178.56
6. Step 6: Final answer
   x = 10,915.52