Finding the Fourth Proportional to 1,206.77, 1,665.32 and 709.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,206.77 : 1,665.32 = 709.30 : x
2. Step 2: Convert to fraction form
   1,206.77/1,665.32 = 709.30/x
3. Step 3: Cross multiply
   1,206.77x = 1,665.32 × 709.30
4. Step 4: Simplify right side
   1,206.77x = 1,181,203.77
5. Step 5: Solve for x
   x = 1,181,203.77/1,206.77
6. Step 6: Final answer
   x = 978.81