Finding the Fourth Proportional to 1,404.88, 1,938.18 and 815.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,404.88 : 1,938.18 = 815.20 : x
2. Step 2: Convert to fraction form
   1,404.88/1,938.18 = 815.20/x
3. Step 3: Cross multiply
   1,404.88x = 1,938.18 × 815.20
4. Step 4: Simplify right side
   1,404.88x = 1,580,004.34
5. Step 5: Solve for x
   x = 1,580,004.34/1,404.88
6. Step 6: Final answer
   x = 1,124.65