Finding the Fourth Proportional to 1,311.77, 1,810.17 and 722.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.77 : 1,810.17 = 722.31 : x
2. Step 2: Convert to fraction form
   1,311.77/1,810.17 = 722.31/x
3. Step 3: Cross multiply
   1,311.77x = 1,810.17 × 722.31
4. Step 4: Simplify right side
   1,311.77x = 1,307,503.89
5. Step 5: Solve for x
   x = 1,307,503.89/1,311.77
6. Step 6: Final answer
   x = 996.75