Finding the Fourth Proportional to 1,215.37, 1,677.41 and 691.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.37 : 1,677.41 = 691.57 : x
2. Step 2: Convert to fraction form
   1,215.37/1,677.41 = 691.57/x
3. Step 3: Cross multiply
   1,215.37x = 1,677.41 × 691.57
4. Step 4: Simplify right side
   1,215.37x = 1,160,046.43
5. Step 5: Solve for x
   x = 1,160,046.43/1,215.37
6. Step 6: Final answer
   x = 954.48