Finding the Fourth Proportional to 1,311.89, 1,967.72 and 618.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.89 : 1,967.72 = 618.12 : x
2. Step 2: Convert to fraction form
   1,311.89/1,967.72 = 618.12/x
3. Step 3: Cross multiply
   1,311.89x = 1,967.72 × 618.12
4. Step 4: Simplify right side
   1,311.89x = 1,216,284.00
5. Step 5: Solve for x
   x = 1,216,284.00/1,311.89
6. Step 6: Final answer
   x = 927.13