Finding the Fourth Proportional to 1,243.06, 1,865.58 and 658.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,243.06 : 1,865.58 = 658.72 : x
2. Step 2: Convert to fraction form
   1,243.06/1,865.58 = 658.72/x
3. Step 3: Cross multiply
   1,243.06x = 1,865.58 × 658.72
4. Step 4: Simplify right side
   1,243.06x = 1,228,894.86
5. Step 5: Solve for x
   x = 1,228,894.86/1,243.06
6. Step 6: Final answer
   x = 988.60