Finding the Fourth Proportional to 6,618.38, 9,931.21 and 3,155.63

Step by Step Solution

1. Step 1: Write the proportion equation
   6,618.38 : 9,931.21 = 3,155.63 : x
2. Step 2: Convert to fraction form
   6,618.38/9,931.21 = 3,155.63/x
3. Step 3: Cross multiply
   6,618.38x = 9,931.21 × 3,155.63
4. Step 4: Simplify right side
   6,618.38x = 31,339,166.67
5. Step 5: Solve for x
   x = 31,339,166.67/6,618.38
6. Step 6: Final answer
   x = 4,735.18