Finding the Fourth Proportional to 1,215.27, 1,677.06 and 691.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.27 : 1,677.06 = 691.31 : x
2. Step 2: Convert to fraction form
   1,215.27/1,677.06 = 691.31/x
3. Step 3: Cross multiply
   1,215.27x = 1,677.06 × 691.31
4. Step 4: Simplify right side
   1,215.27x = 1,159,372.54
5. Step 5: Solve for x
   x = 1,159,372.54/1,215.27
6. Step 6: Final answer
   x = 954.00