Finding the Fourth Proportional to 11,820.72, 16,312.68 and 9,171.72

Step by Step Solution

1. Step 1: Write the proportion equation
   11,820.72 : 16,312.68 = 9,171.72 : x
2. Step 2: Convert to fraction form
   11,820.72/16,312.68 = 9,171.72/x
3. Step 3: Cross multiply
   11,820.72x = 16,312.68 × 9,171.72
4. Step 4: Simplify right side
   11,820.72x = 149,615,333.41
5. Step 5: Solve for x
   x = 149,615,333.41/11,820.72
6. Step 6: Final answer
   x = 12,657.04