Finding the Fourth Proportional to 1,188.82, 1,640.17 and 691.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,188.82 : 1,640.17 = 691.05 : x
2. Step 2: Convert to fraction form
   1,188.82/1,640.17 = 691.05/x
3. Step 3: Cross multiply
   1,188.82x = 1,640.17 × 691.05
4. Step 4: Simplify right side
   1,188.82x = 1,133,442.53
5. Step 5: Solve for x
   x = 1,133,442.53/1,188.82
6. Step 6: Final answer
   x = 953.42