Finding the Fourth Proportional to 1,136.15, 1,567.83 and 638.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,136.15 : 1,567.83 = 638.94 : x
2. Step 2: Convert to fraction form
   1,136.15/1,567.83 = 638.94/x
3. Step 3: Cross multiply
   1,136.15x = 1,567.83 × 638.94
4. Step 4: Simplify right side
   1,136.15x = 1,001,749.30
5. Step 5: Solve for x
   x = 1,001,749.30/1,136.15
6. Step 6: Final answer
   x = 881.71