Finding the Fourth Proportional to 2,459.86, 3,688.40 and 815.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,459.86 : 3,688.40 = 815.96 : x
2. Step 2: Convert to fraction form
   2,459.86/3,688.40 = 815.96/x
3. Step 3: Cross multiply
   2,459.86x = 3,688.40 × 815.96
4. Step 4: Simplify right side
   2,459.86x = 3,009,586.86
5. Step 5: Solve for x
   x = 3,009,586.86/2,459.86
6. Step 6: Final answer
   x = 1,223.48