Finding the Fourth Proportional to 1,215.57, 1,677.29 and 684.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.57 : 1,677.29 = 684.35 : x
2. Step 2: Convert to fraction form
   1,215.57/1,677.29 = 684.35/x
3. Step 3: Cross multiply
   1,215.57x = 1,677.29 × 684.35
4. Step 4: Simplify right side
   1,215.57x = 1,147,853.41
5. Step 5: Solve for x
   x = 1,147,853.41/1,215.57
6. Step 6: Final answer
   x = 944.29