Finding the Fourth Proportional to 12,789.64, 17,656.59 and 8,972.96

Step by Step Solution

1. Step 1: Write the proportion equation
   12,789.64 : 17,656.59 = 8,972.96 : x
2. Step 2: Convert to fraction form
   12,789.64/17,656.59 = 8,972.96/x
3. Step 3: Cross multiply
   12,789.64x = 17,656.59 × 8,972.96
4. Step 4: Simplify right side
   12,789.64x = 158,431,875.81
5. Step 5: Solve for x
   x = 158,431,875.81/12,789.64
6. Step 6: Final answer
   x = 12,387.52