Finding the Fourth Proportional to 1,188.98, 1,640.42 and 769.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,188.98 : 1,640.42 = 769.33 : x
2. Step 2: Convert to fraction form
   1,188.98/1,640.42 = 769.33/x
3. Step 3: Cross multiply
   1,188.98x = 1,640.42 × 769.33
4. Step 4: Simplify right side
   1,188.98x = 1,262,025.41
5. Step 5: Solve for x
   x = 1,262,025.41/1,188.98
6. Step 6: Final answer
   x = 1,061.44