Finding the Fourth Proportional to 3,123.84, 4,685.67 and 815.34

Step by Step Solution

1. Step 1: Write the proportion equation
   3,123.84 : 4,685.67 = 815.34 : x
2. Step 2: Convert to fraction form
   3,123.84/4,685.67 = 815.34/x
3. Step 3: Cross multiply
   3,123.84x = 4,685.67 × 815.34
4. Step 4: Simplify right side
   3,123.84x = 3,820,414.18
5. Step 5: Solve for x
   x = 3,820,414.18/3,123.84
6. Step 6: Final answer
   x = 1,222.99