Finding the Fourth Proportional to 1,136.43, 1,568.33 and 639.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,136.43 : 1,568.33 = 639.15 : x
2. Step 2: Convert to fraction form
   1,136.43/1,568.33 = 639.15/x
3. Step 3: Cross multiply
   1,136.43x = 1,568.33 × 639.15
4. Step 4: Simplify right side
   1,136.43x = 1,002,398.12
5. Step 5: Solve for x
   x = 1,002,398.12/1,136.43
6. Step 6: Final answer
   x = 882.06