Finding the Fourth Proportional to 1,122.72, 1,549.36 and 680.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,122.72 : 1,549.36 = 680.31 : x
2. Step 2: Convert to fraction form
   1,122.72/1,549.36 = 680.31/x
3. Step 3: Cross multiply
   1,122.72x = 1,549.36 × 680.31
4. Step 4: Simplify right side
   1,122.72x = 1,054,045.10
5. Step 5: Solve for x
   x = 1,054,045.10/1,122.72
6. Step 6: Final answer
   x = 938.83