Finding the Fourth Proportional to 1,206.72, 1,664.71 and 709.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,206.72 : 1,664.71 = 709.35 : x
2. Step 2: Convert to fraction form
   1,206.72/1,664.71 = 709.35/x
3. Step 3: Cross multiply
   1,206.72x = 1,664.71 × 709.35
4. Step 4: Simplify right side
   1,206.72x = 1,180,862.04
5. Step 5: Solve for x
   x = 1,180,862.04/1,206.72
6. Step 6: Final answer
   x = 978.57