Finding the Fourth Proportional to 1,222.55, 1,685.36 and 872.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.55 : 1,685.36 = 872.63 : x
2. Step 2: Convert to fraction form
   1,222.55/1,685.36 = 872.63/x
3. Step 3: Cross multiply
   1,222.55x = 1,685.36 × 872.63
4. Step 4: Simplify right side
   1,222.55x = 1,470,689.45
5. Step 5: Solve for x
   x = 1,470,689.45/1,222.55
6. Step 6: Final answer
   x = 1,202.97