Finding the Fourth Proportional to 1,072.76, 1,480.89 and 630.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,072.76 : 1,480.89 = 630.70 : x
2. Step 2: Convert to fraction form
   1,072.76/1,480.89 = 630.70/x
3. Step 3: Cross multiply
   1,072.76x = 1,480.89 × 630.70
4. Step 4: Simplify right side
   1,072.76x = 933,997.32
5. Step 5: Solve for x
   x = 933,997.32/1,072.76
6. Step 6: Final answer
   x = 870.65