Finding the Fourth Proportional to 1,058.48, 1,460.28 and 638.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,058.48 : 1,460.28 = 638.72 : x
2. Step 2: Convert to fraction form
   1,058.48/1,460.28 = 638.72/x
3. Step 3: Cross multiply
   1,058.48x = 1,460.28 × 638.72
4. Step 4: Simplify right side
   1,058.48x = 932,710.04
5. Step 5: Solve for x
   x = 932,710.04/1,058.48
6. Step 6: Final answer
   x = 881.18