Finding the Fourth Proportional to 1,200.57, 1,656.72 and 669.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.57 : 1,656.72 = 669.42 : x
2. Step 2: Convert to fraction form
   1,200.57/1,656.72 = 669.42/x
3. Step 3: Cross multiply
   1,200.57x = 1,656.72 × 669.42
4. Step 4: Simplify right side
   1,200.57x = 1,109,038.16
5. Step 5: Solve for x
   x = 1,109,038.16/1,200.57
6. Step 6: Final answer
   x = 923.76