Finding the Fourth Proportional to 1,312.24, 1,810.86 and 722.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,312.24 : 1,810.86 = 722.78 : x
2. Step 2: Convert to fraction form
   1,312.24/1,810.86 = 722.78/x
3. Step 3: Cross multiply
   1,312.24x = 1,810.86 × 722.78
4. Step 4: Simplify right side
   1,312.24x = 1,308,853.39
5. Step 5: Solve for x
   x = 1,308,853.39/1,312.24
6. Step 6: Final answer
   x = 997.42