Finding the Fourth Proportional to 1,136.53, 1,568.41 and 639.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,136.53 : 1,568.41 = 639.15 : x
2. Step 2: Convert to fraction form
   1,136.53/1,568.41 = 639.15/x
3. Step 3: Cross multiply
   1,136.53x = 1,568.41 × 639.15
4. Step 4: Simplify right side
   1,136.53x = 1,002,449.25
5. Step 5: Solve for x
   x = 1,002,449.25/1,136.53
6. Step 6: Final answer
   x = 882.03