Finding the Fourth Proportional to 681.55, 1,022.15 and 315.98

Step by Step Solution

1. Step 1: Write the proportion equation
   681.55 : 1,022.15 = 315.98 : x
2. Step 2: Convert to fraction form
   681.55/1,022.15 = 315.98/x
3. Step 3: Cross multiply
   681.55x = 1,022.15 × 315.98
4. Step 4: Simplify right side
   681.55x = 322,978.96
5. Step 5: Solve for x
   x = 322,978.96/681.55
6. Step 6: Final answer
   x = 473.89