Finding the Fourth Proportional to 1,222.52, 1,686.72 and 718.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.52 : 1,686.72 = 718.14 : x
2. Step 2: Convert to fraction form
   1,222.52/1,686.72 = 718.14/x
3. Step 3: Cross multiply
   1,222.52x = 1,686.72 × 718.14
4. Step 4: Simplify right side
   1,222.52x = 1,211,305.38
5. Step 5: Solve for x
   x = 1,211,305.38/1,222.52
6. Step 6: Final answer
   x = 990.83