Finding the Fourth Proportional to 9,286.74, 13,917.15 and 5,128.74

Step by Step Solution

1. Step 1: Write the proportion equation
   9,286.74 : 13,917.15 = 5,128.74 : x
2. Step 2: Convert to fraction form
   9,286.74/13,917.15 = 5,128.74/x
3. Step 3: Cross multiply
   9,286.74x = 13,917.15 × 5,128.74
4. Step 4: Simplify right side
   9,286.74x = 71,377,443.89
5. Step 5: Solve for x
   x = 71,377,443.89/9,286.74
6. Step 6: Final answer
   x = 7,685.95