Finding the Fourth Proportional to 1,056.98, 1,582.83 and 640.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,056.98 : 1,582.83 = 640.29 : x
2. Step 2: Convert to fraction form
   1,056.98/1,582.83 = 640.29/x
3. Step 3: Cross multiply
   1,056.98x = 1,582.83 × 640.29
4. Step 4: Simplify right side
   1,056.98x = 1,013,470.22
5. Step 5: Solve for x
   x = 1,013,470.22/1,056.98
6. Step 6: Final answer
   x = 958.84