Finding the Fourth Proportional to 8,712.64, 12,017.31 and 5,357.29

Step by Step Solution

1. Step 1: Write the proportion equation
   8,712.64 : 12,017.31 = 5,357.29 : x
2. Step 2: Convert to fraction form
   8,712.64/12,017.31 = 5,357.29/x
3. Step 3: Cross multiply
   8,712.64x = 12,017.31 × 5,357.29
4. Step 4: Simplify right side
   8,712.64x = 64,380,214.69
5. Step 5: Solve for x
   x = 64,380,214.69/8,712.64
6. Step 6: Final answer
   x = 7,389.29