Finding the Fourth Proportional to 8,691.42, 13,038.15 and 3,147.38

Step by Step Solution

1. Step 1: Write the proportion equation
   8,691.42 : 13,038.15 = 3,147.38 : x
2. Step 2: Convert to fraction form
   8,691.42/13,038.15 = 3,147.38/x
3. Step 3: Cross multiply
   8,691.42x = 13,038.15 × 3,147.38
4. Step 4: Simplify right side
   8,691.42x = 41,036,012.55
5. Step 5: Solve for x
   x = 41,036,012.55/8,691.42
6. Step 6: Final answer
   x = 4,721.44