Finding the Fourth Proportional to 1,308.61, 1,960.35 and 658.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,308.61 : 1,960.35 = 658.72 : x
2. Step 2: Convert to fraction form
   1,308.61/1,960.35 = 658.72/x
3. Step 3: Cross multiply
   1,308.61x = 1,960.35 × 658.72
4. Step 4: Simplify right side
   1,308.61x = 1,291,321.75
5. Step 5: Solve for x
   x = 1,291,321.75/1,308.61
6. Step 6: Final answer
   x = 986.79