Finding the Fourth Proportional to 1,057.76, 1,460.31 and 638.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,057.76 : 1,460.31 = 638.24 : x
2. Step 2: Convert to fraction form
   1,057.76/1,460.31 = 638.24/x
3. Step 3: Cross multiply
   1,057.76x = 1,460.31 × 638.24
4. Step 4: Simplify right side
   1,057.76x = 932,022.15
5. Step 5: Solve for x
   x = 932,022.15/1,057.76
6. Step 6: Final answer
   x = 881.12