Finding the Fourth Proportional to 1,222.32, 1,686.78 and 959.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.32 : 1,686.78 = 959.88 : x
2. Step 2: Convert to fraction form
   1,222.32/1,686.78 = 959.88/x
3. Step 3: Cross multiply
   1,222.32x = 1,686.78 × 959.88
4. Step 4: Simplify right side
   1,222.32x = 1,619,106.39
5. Step 5: Solve for x
   x = 1,619,106.39/1,222.32
6. Step 6: Final answer
   x = 1,324.62