Finding the Fourth Proportional to 1,247.83, 1,722.00 and 688.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,247.83 : 1,722.00 = 688.28 : x
2. Step 2: Convert to fraction form
   1,247.83/1,722.00 = 688.28/x
3. Step 3: Cross multiply
   1,247.83x = 1,722.00 × 688.28
4. Step 4: Simplify right side
   1,247.83x = 1,185,221.82
5. Step 5: Solve for x
   x = 1,185,221.82/1,247.83
6. Step 6: Final answer
   x = 949.83