Finding the Fourth Proportional to 1,219.41, 1,682.69 and 688.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,219.41 : 1,682.69 = 688.23 : x
2. Step 2: Convert to fraction form
   1,219.41/1,682.69 = 688.23/x
3. Step 3: Cross multiply
   1,219.41x = 1,682.69 × 688.23
4. Step 4: Simplify right side
   1,219.41x = 1,158,074.30
5. Step 5: Solve for x
   x = 1,158,074.30/1,219.41
6. Step 6: Final answer
   x = 949.70