Finding the Fourth Proportional to 1,224.52, 1,689.83 and 664.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,224.52 : 1,689.83 = 664.99 : x
2. Step 2: Convert to fraction form
   1,224.52/1,689.83 = 664.99/x
3. Step 3: Cross multiply
   1,224.52x = 1,689.83 × 664.99
4. Step 4: Simplify right side
   1,224.52x = 1,123,714.32
5. Step 5: Solve for x
   x = 1,123,714.32/1,224.52
6. Step 6: Final answer
   x = 917.68