Finding the Fourth Proportional to 1,433.30, 2,147.90 and 815.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,433.30 : 2,147.90 = 815.70 : x
2. Step 2: Convert to fraction form
   1,433.30/2,147.90 = 815.70/x
3. Step 3: Cross multiply
   1,433.30x = 2,147.90 × 815.70
4. Step 4: Simplify right side
   1,433.30x = 1,752,042.03
5. Step 5: Solve for x
   x = 1,752,042.03/1,433.30
6. Step 6: Final answer
   x = 1,222.38