Finding the Fourth Proportional to 1,223.56, 1,688.78 and 757.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.56 : 1,688.78 = 757.48 : x
2. Step 2: Convert to fraction form
   1,223.56/1,688.78 = 757.48/x
3. Step 3: Cross multiply
   1,223.56x = 1,688.78 × 757.48
4. Step 4: Simplify right side
   1,223.56x = 1,279,217.07
5. Step 5: Solve for x
   x = 1,279,217.07/1,223.56
6. Step 6: Final answer
   x = 1,045.49