Finding the Fourth Proportional to 1,136.73, 1,568.76 and 639.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,136.73 : 1,568.76 = 639.36 : x
2. Step 2: Convert to fraction form
   1,136.73/1,568.76 = 639.36/x
3. Step 3: Cross multiply
   1,136.73x = 1,568.76 × 639.36
4. Step 4: Simplify right side
   1,136.73x = 1,003,002.39
5. Step 5: Solve for x
   x = 1,003,002.39/1,136.73
6. Step 6: Final answer
   x = 882.36