Finding the Fourth Proportional to 1,072.31, 1,479.78 and 630.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,072.31 : 1,479.78 = 630.46 : x
2. Step 2: Convert to fraction form
   1,072.31/1,479.78 = 630.46/x
3. Step 3: Cross multiply
   1,072.31x = 1,479.78 × 630.46
4. Step 4: Simplify right side
   1,072.31x = 932,946.59
5. Step 5: Solve for x
   x = 932,946.59/1,072.31
6. Step 6: Final answer
   x = 870.04