Finding the Fourth Proportional to 9,678.32, 13,369.60 and 9,318.72

Step by Step Solution

1. Step 1: Write the proportion equation
   9,678.32 : 13,369.60 = 9,318.72 : x
2. Step 2: Convert to fraction form
   9,678.32/13,369.60 = 9,318.72/x
3. Step 3: Cross multiply
   9,678.32x = 13,369.60 × 9,318.72
4. Step 4: Simplify right side
   9,678.32x = 124,587,558.91
5. Step 5: Solve for x
   x = 124,587,558.91/9,678.32
6. Step 6: Final answer
   x = 12,872.85