Finding the Fourth Proportional to 1,007.51, 1,391.04 and 658.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.51 : 1,391.04 = 658.80 : x
2. Step 2: Convert to fraction form
   1,007.51/1,391.04 = 658.80/x
3. Step 3: Cross multiply
   1,007.51x = 1,391.04 × 658.80
4. Step 4: Simplify right side
   1,007.51x = 916,417.15
5. Step 5: Solve for x
   x = 916,417.15/1,007.51
6. Step 6: Final answer
   x = 909.59