Finding the Fourth Proportional to 1,312.55, 1,965.98 and 618.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,312.55 : 1,965.98 = 618.17 : x
2. Step 2: Convert to fraction form
   1,312.55/1,965.98 = 618.17/x
3. Step 3: Cross multiply
   1,312.55x = 1,965.98 × 618.17
4. Step 4: Simplify right side
   1,312.55x = 1,215,309.86
5. Step 5: Solve for x
   x = 1,215,309.86/1,312.55
6. Step 6: Final answer
   x = 925.92