Finding the Fourth Proportional to 8,397.59, 12,588.17 and 3,128.74

Step by Step Solution

1. Step 1: Write the proportion equation
   8,397.59 : 12,588.17 = 3,128.74 : x
2. Step 2: Convert to fraction form
   8,397.59/12,588.17 = 3,128.74/x
3. Step 3: Cross multiply
   8,397.59x = 12,588.17 × 3,128.74
4. Step 4: Simplify right side
   8,397.59x = 39,385,032.42
5. Step 5: Solve for x
   x = 39,385,032.42/8,397.59
6. Step 6: Final answer
   x = 4,690.04