Finding the Fourth Proportional to 5,187.58, 7,148.59 and 3,691.31

Step by Step Solution

1. Step 1: Write the proportion equation
   5,187.58 : 7,148.59 = 3,691.31 : x
2. Step 2: Convert to fraction form
   5,187.58/7,148.59 = 3,691.31/x
3. Step 3: Cross multiply
   5,187.58x = 7,148.59 × 3,691.31
4. Step 4: Simplify right side
   5,187.58x = 26,387,616.78
5. Step 5: Solve for x
   x = 26,387,616.78/5,187.58
6. Step 6: Final answer
   x = 5,086.69