Finding the Fourth Proportional to 1,012.55, 1,397.89 and 658.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.55 : 1,397.89 = 658.79 : x
2. Step 2: Convert to fraction form
   1,012.55/1,397.89 = 658.79/x
3. Step 3: Cross multiply
   1,012.55x = 1,397.89 × 658.79
4. Step 4: Simplify right side
   1,012.55x = 920,907.32
5. Step 5: Solve for x
   x = 920,907.32/1,012.55
6. Step 6: Final answer
   x = 909.49