Finding the Fourth Proportional to 2,147.00, 3,220.34 and 685.76

Step by Step Solution

1. Step 1: Write the proportion equation
   2,147.00 : 3,220.34 = 685.76 : x
2. Step 2: Convert to fraction form
   2,147.00/3,220.34 = 685.76/x
3. Step 3: Cross multiply
   2,147.00x = 3,220.34 × 685.76
4. Step 4: Simplify right side
   2,147.00x = 2,208,360.83
5. Step 5: Solve for x
   x = 2,208,360.83/2,147.00
6. Step 6: Final answer
   x = 1,028.58