Finding the Fourth Proportional to 1,239.50, 1,710.54 and 680.00

Step by Step Solution

1. Step 1: Write the proportion equation
   1,239.50 : 1,710.54 = 680.00 : x
2. Step 2: Convert to fraction form
   1,239.50/1,710.54 = 680.00/x
3. Step 3: Cross multiply
   1,239.50x = 1,710.54 × 680.00
4. Step 4: Simplify right side
   1,239.50x = 1,163,171.48
5. Step 5: Solve for x
   x = 1,163,171.48/1,239.50
6. Step 6: Final answer
   x = 938.42