Finding the Fourth Proportional to 1,030.72, 1,421.96 and 616.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,030.72 : 1,421.96 = 616.72 : x
2. Step 2: Convert to fraction form
   1,030.72/1,421.96 = 616.72/x
3. Step 3: Cross multiply
   1,030.72x = 1,421.96 × 616.72
4. Step 4: Simplify right side
   1,030.72x = 876,951.17
5. Step 5: Solve for x
   x = 876,951.17/1,030.72
6. Step 6: Final answer
   x = 850.81