Finding the Fourth Proportional to 1,072.30, 1,479.43 and 630.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,072.30 : 1,479.43 = 630.31 : x
2. Step 2: Convert to fraction form
   1,072.30/1,479.43 = 630.31/x
3. Step 3: Cross multiply
   1,072.30x = 1,479.43 × 630.31
4. Step 4: Simplify right side
   1,072.30x = 932,499.52
5. Step 5: Solve for x
   x = 932,499.52/1,072.30
6. Step 6: Final answer
   x = 869.63