Finding the Fourth Proportional to 1,206.69, 1,662.89 and 856.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,206.69 : 1,662.89 = 856.77 : x
2. Step 2: Convert to fraction form
   1,206.69/1,662.89 = 856.77/x
3. Step 3: Cross multiply
   1,206.69x = 1,662.89 × 856.77
4. Step 4: Simplify right side
   1,206.69x = 1,424,714.27
5. Step 5: Solve for x
   x = 1,424,714.27/1,206.69
6. Step 6: Final answer
   x = 1,180.68