Finding the Fourth Proportional to 1,419.45, 2,128.06 and 688.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,419.45 : 2,128.06 = 688.83 : x
2. Step 2: Convert to fraction form
   1,419.45/2,128.06 = 688.83/x
3. Step 3: Cross multiply
   1,419.45x = 2,128.06 × 688.83
4. Step 4: Simplify right side
   1,419.45x = 1,465,871.57
5. Step 5: Solve for x
   x = 1,465,871.57/1,419.45
6. Step 6: Final answer
   x = 1,032.70