Finding the Fourth Proportional to 1,011.94, 1,396.15 and 618.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,011.94 : 1,396.15 = 618.69 : x
2. Step 2: Convert to fraction form
   1,011.94/1,396.15 = 618.69/x
3. Step 3: Cross multiply
   1,011.94x = 1,396.15 × 618.69
4. Step 4: Simplify right side
   1,011.94x = 863,784.04
5. Step 5: Solve for x
   x = 863,784.04/1,011.94
6. Step 6: Final answer
   x = 853.59