Finding the Fourth Proportional to 1,057.92, 1,459.98 and 638.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,057.92 : 1,459.98 = 638.34 : x
2. Step 2: Convert to fraction form
   1,057.92/1,459.98 = 638.34/x
3. Step 3: Cross multiply
   1,057.92x = 1,459.98 × 638.34
4. Step 4: Simplify right side
   1,057.92x = 931,963.63
5. Step 5: Solve for x
   x = 931,963.63/1,057.92
6. Step 6: Final answer
   x = 880.94