Finding the Fourth Proportional to 2,459.50, 3,688.80 and 815.86

Step by Step Solution

1. Step 1: Write the proportion equation
   2,459.50 : 3,688.80 = 815.86 : x
2. Step 2: Convert to fraction form
   2,459.50/3,688.80 = 815.86/x
3. Step 3: Cross multiply
   2,459.50x = 3,688.80 × 815.86
4. Step 4: Simplify right side
   2,459.50x = 3,009,544.37
5. Step 5: Solve for x
   x = 3,009,544.37/2,459.50
6. Step 6: Final answer
   x = 1,223.64