Finding the Fourth Proportional to 1,011.27, 1,395.72 and 618.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,011.27 : 1,395.72 = 618.51 : x
2. Step 2: Convert to fraction form
   1,011.27/1,395.72 = 618.51/x
3. Step 3: Cross multiply
   1,011.27x = 1,395.72 × 618.51
4. Step 4: Simplify right side
   1,011.27x = 863,266.78
5. Step 5: Solve for x
   x = 863,266.78/1,011.27
6. Step 6: Final answer
   x = 853.65