Finding the Fourth Proportional to 1,189.02, 1,640.59 and 691.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.02 : 1,640.59 = 691.72 : x
2. Step 2: Convert to fraction form
   1,189.02/1,640.59 = 691.72/x
3. Step 3: Cross multiply
   1,189.02x = 1,640.59 × 691.72
4. Step 4: Simplify right side
   1,189.02x = 1,134,828.91
5. Step 5: Solve for x
   x = 1,134,828.91/1,189.02
6. Step 6: Final answer
   x = 954.42