Finding the Fourth Proportional to 1,383.83, 2,072.96 and 688.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,383.83 : 2,072.96 = 688.39 : x
2. Step 2: Convert to fraction form
   1,383.83/2,072.96 = 688.39/x
3. Step 3: Cross multiply
   1,383.83x = 2,072.96 × 688.39
4. Step 4: Simplify right side
   1,383.83x = 1,426,998.89
5. Step 5: Solve for x
   x = 1,426,998.89/1,383.83
6. Step 6: Final answer
   x = 1,031.20