Finding the Fourth Proportional to 1,212.82, 1,673.76 and 688.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,212.82 : 1,673.76 = 688.96 : x
2. Step 2: Convert to fraction form
   1,212.82/1,673.76 = 688.96/x
3. Step 3: Cross multiply
   1,212.82x = 1,673.76 × 688.96
4. Step 4: Simplify right side
   1,212.82x = 1,153,153.69
5. Step 5: Solve for x
   x = 1,153,153.69/1,212.82
6. Step 6: Final answer
   x = 950.80