Finding the Fourth Proportional to 1,311.89, 1,810.45 and 722.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.89 : 1,810.45 = 722.47 : x
2. Step 2: Convert to fraction form
   1,311.89/1,810.45 = 722.47/x
3. Step 3: Cross multiply
   1,311.89x = 1,810.45 × 722.47
4. Step 4: Simplify right side
   1,311.89x = 1,307,995.81
5. Step 5: Solve for x
   x = 1,307,995.81/1,311.89
6. Step 6: Final answer
   x = 997.03