Finding the Fourth Proportional to 1,200.78, 1,657.89 and 886.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.78 : 1,657.89 = 886.08 : x
2. Step 2: Convert to fraction form
   1,200.78/1,657.89 = 886.08/x
3. Step 3: Cross multiply
   1,200.78x = 1,657.89 × 886.08
4. Step 4: Simplify right side
   1,200.78x = 1,469,023.17
5. Step 5: Solve for x
   x = 1,469,023.17/1,200.78
6. Step 6: Final answer
   x = 1,223.39