Finding the Fourth Proportional to 1,189.98, 1,642.04 and 658.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.98 : 1,642.04 = 658.78 : x
2. Step 2: Convert to fraction form
   1,189.98/1,642.04 = 658.78/x
3. Step 3: Cross multiply
   1,189.98x = 1,642.04 × 658.78
4. Step 4: Simplify right side
   1,189.98x = 1,081,731.61
5. Step 5: Solve for x
   x = 1,081,731.61/1,189.98
6. Step 6: Final answer
   x = 909.04