Finding the Fourth Proportional to 1,008.69, 1,391.61 and 658.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.69 : 1,391.61 = 658.77 : x
2. Step 2: Convert to fraction form
   1,008.69/1,391.61 = 658.77/x
3. Step 3: Cross multiply
   1,008.69x = 1,391.61 × 658.77
4. Step 4: Simplify right side
   1,008.69x = 916,748.17
5. Step 5: Solve for x
   x = 916,748.17/1,008.69
6. Step 6: Final answer
   x = 908.85