Finding the Fourth Proportional to 1,192.71, 1,645.61 and 688.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,192.71 : 1,645.61 = 688.54 : x
2. Step 2: Convert to fraction form
   1,192.71/1,645.61 = 688.54/x
3. Step 3: Cross multiply
   1,192.71x = 1,645.61 × 688.54
4. Step 4: Simplify right side
   1,192.71x = 1,133,068.31
5. Step 5: Solve for x
   x = 1,133,068.31/1,192.71
6. Step 6: Final answer
   x = 949.99