Finding the Fourth Proportional to 1,142.81, 1,577.09 and 722.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.81 : 1,577.09 = 722.72 : x
2. Step 2: Convert to fraction form
   1,142.81/1,577.09 = 722.72/x
3. Step 3: Cross multiply
   1,142.81x = 1,577.09 × 722.72
4. Step 4: Simplify right side
   1,142.81x = 1,139,794.48
5. Step 5: Solve for x
   x = 1,139,794.48/1,142.81
6. Step 6: Final answer
   x = 997.36