Finding the Fourth Proportional to 15,554.50, 21,468.56 and 9,178.72

Step by Step Solution

1. Step 1: Write the proportion equation
   15,554.50 : 21,468.56 = 9,178.72 : x
2. Step 2: Convert to fraction form
   15,554.50/21,468.56 = 9,178.72/x
3. Step 3: Cross multiply
   15,554.50x = 21,468.56 × 9,178.72
4. Step 4: Simplify right side
   15,554.50x = 197,053,747.81
5. Step 5: Solve for x
   x = 197,053,747.81/15,554.50
6. Step 6: Final answer
   x = 12,668.60