Finding the Fourth Proportional to 2,113.62, 3,170.37 and 815.37

Step by Step Solution

1. Step 1: Write the proportion equation
   2,113.62 : 3,170.37 = 815.37 : x
2. Step 2: Convert to fraction form
   2,113.62/3,170.37 = 815.37/x
3. Step 3: Cross multiply
   2,113.62x = 3,170.37 × 815.37
4. Step 4: Simplify right side
   2,113.62x = 2,585,024.59
5. Step 5: Solve for x
   x = 2,585,024.59/2,113.62
6. Step 6: Final answer
   x = 1,223.03