Finding the Fourth Proportional to 5,209.31, 7,814.37 and 2,131.31

Step by Step Solution

1. Step 1: Write the proportion equation
   5,209.31 : 7,814.37 = 2,131.31 : x
2. Step 2: Convert to fraction form
   5,209.31/7,814.37 = 2,131.31/x
3. Step 3: Cross multiply
   5,209.31x = 7,814.37 × 2,131.31
4. Step 4: Simplify right side
   5,209.31x = 16,654,872.45
5. Step 5: Solve for x
   x = 16,654,872.45/5,209.31
6. Step 6: Final answer
   x = 3,197.13