Finding the Fourth Proportional to 5,127.90, 7,691.31 and 1,665.15

Step by Step Solution

1. Step 1: Write the proportion equation
   5,127.90 : 7,691.31 = 1,665.15 : x
2. Step 2: Convert to fraction form
   5,127.90/7,691.31 = 1,665.15/x
3. Step 3: Cross multiply
   5,127.90x = 7,691.31 × 1,665.15
4. Step 4: Simplify right side
   5,127.90x = 12,807,184.85
5. Step 5: Solve for x
   x = 12,807,184.85/5,127.90
6. Step 6: Final answer
   x = 2,497.55