Finding the Fourth Proportional to 1,200.69, 1,656.90 and 669.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.69 : 1,656.90 = 669.55 : x
2. Step 2: Convert to fraction form
   1,200.69/1,656.90 = 669.55/x
3. Step 3: Cross multiply
   1,200.69x = 1,656.90 × 669.55
4. Step 4: Simplify right side
   1,200.69x = 1,109,373.25
5. Step 5: Solve for x
   x = 1,109,373.25/1,200.69
6. Step 6: Final answer
   x = 923.95