Finding the Fourth Proportional to 1,142.27, 1,576.33 and 618.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.27 : 1,576.33 = 618.30 : x
2. Step 2: Convert to fraction form
   1,142.27/1,576.33 = 618.30/x
3. Step 3: Cross multiply
   1,142.27x = 1,576.33 × 618.30
4. Step 4: Simplify right side
   1,142.27x = 974,644.84
5. Step 5: Solve for x
   x = 974,644.84/1,142.27
6. Step 6: Final answer
   x = 853.25