Finding the Fourth Proportional to 1,209.69, 1,669.37 and 657.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,209.69 : 1,669.37 = 657.69 : x
2. Step 2: Convert to fraction form
   1,209.69/1,669.37 = 657.69/x
3. Step 3: Cross multiply
   1,209.69x = 1,669.37 × 657.69
4. Step 4: Simplify right side
   1,209.69x = 1,097,923.78
5. Step 5: Solve for x
   x = 1,097,923.78/1,209.69
6. Step 6: Final answer
   x = 907.61