Finding the Fourth Proportional to 1,216.72, 1,677.39 and 917.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,216.72 : 1,677.39 = 917.83 : x
2. Step 2: Convert to fraction form
   1,216.72/1,677.39 = 917.83/x
3. Step 3: Cross multiply
   1,216.72x = 1,677.39 × 917.83
4. Step 4: Simplify right side
   1,216.72x = 1,539,550.48
5. Step 5: Solve for x
   x = 1,539,550.48/1,216.72
6. Step 6: Final answer
   x = 1,265.33