Finding the Fourth Proportional to 1,222.49, 1,687.42 and 824.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.49 : 1,687.42 = 824.73 : x
2. Step 2: Convert to fraction form
   1,222.49/1,687.42 = 824.73/x
3. Step 3: Cross multiply
   1,222.49x = 1,687.42 × 824.73
4. Step 4: Simplify right side
   1,222.49x = 1,391,653.34
5. Step 5: Solve for x
   x = 1,391,653.34/1,222.49
6. Step 6: Final answer
   x = 1,138.38