Finding the Fourth Proportional to 1,243.89, 1,715.85 and 824.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,243.89 : 1,715.85 = 824.31 : x
2. Step 2: Convert to fraction form
   1,243.89/1,715.85 = 824.31/x
3. Step 3: Cross multiply
   1,243.89x = 1,715.85 × 824.31
4. Step 4: Simplify right side
   1,243.89x = 1,414,392.31
5. Step 5: Solve for x
   x = 1,414,392.31/1,243.89
6. Step 6: Final answer
   x = 1,137.07