Finding the Fourth Proportional to 1,189.02, 1,640.78 and 657.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.02 : 1,640.78 = 657.88 : x
2. Step 2: Convert to fraction form
   1,189.02/1,640.78 = 657.88/x
3. Step 3: Cross multiply
   1,189.02x = 1,640.78 × 657.88
4. Step 4: Simplify right side
   1,189.02x = 1,079,433.89
5. Step 5: Solve for x
   x = 1,079,433.89/1,189.02
6. Step 6: Final answer
   x = 907.83