Finding the Fourth Proportional to 1,219.27, 1,682.50 and 688.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,219.27 : 1,682.50 = 688.12 : x
2. Step 2: Convert to fraction form
   1,219.27/1,682.50 = 688.12/x
3. Step 3: Cross multiply
   1,219.27x = 1,682.50 × 688.12
4. Step 4: Simplify right side
   1,219.27x = 1,157,761.90
5. Step 5: Solve for x
   x = 1,157,761.90/1,219.27
6. Step 6: Final answer
   x = 949.55