Finding the Fourth Proportional to 2,456.91, 3,686.01 and 813.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,456.91 : 3,686.01 = 813.91 : x
2. Step 2: Convert to fraction form
   2,456.91/3,686.01 = 813.91/x
3. Step 3: Cross multiply
   2,456.91x = 3,686.01 × 813.91
4. Step 4: Simplify right side
   2,456.91x = 3,000,080.40
5. Step 5: Solve for x
   x = 3,000,080.40/2,456.91
6. Step 6: Final answer
   x = 1,221.08