Finding the Fourth Proportional to 1,142.72, 1,576.96 and 618.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.72 : 1,576.96 = 618.75 : x
2. Step 2: Convert to fraction form
   1,142.72/1,576.96 = 618.75/x
3. Step 3: Cross multiply
   1,142.72x = 1,576.96 × 618.75
4. Step 4: Simplify right side
   1,142.72x = 975,742.45
5. Step 5: Solve for x
   x = 975,742.45/1,142.72
6. Step 6: Final answer
   x = 853.88