Finding the Fourth Proportional to 1,189.85, 1,641.96 and 658.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.85 : 1,641.96 = 658.72 : x
2. Step 2: Convert to fraction form
   1,189.85/1,641.96 = 658.72/x
3. Step 3: Cross multiply
   1,189.85x = 1,641.96 × 658.72
4. Step 4: Simplify right side
   1,189.85x = 1,081,591.89
5. Step 5: Solve for x
   x = 1,081,591.89/1,189.85
6. Step 6: Final answer
   x = 909.02