Finding the Fourth Proportional to 1,206.72, 1,665.72 and 858.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,206.72 : 1,665.72 = 858.48 : x
2. Step 2: Convert to fraction form
   1,206.72/1,665.72 = 858.48/x
3. Step 3: Cross multiply
   1,206.72x = 1,665.72 × 858.48
4. Step 4: Simplify right side
   1,206.72x = 1,429,987.31
5. Step 5: Solve for x
   x = 1,429,987.31/1,206.72
6. Step 6: Final answer
   x = 1,185.02