Finding the Fourth Proportional to 1,404.64, 1,938.42 and 815.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,404.64 : 1,938.42 = 815.35 : x
2. Step 2: Convert to fraction form
   1,404.64/1,938.42 = 815.35/x
3. Step 3: Cross multiply
   1,404.64x = 1,938.42 × 815.35
4. Step 4: Simplify right side
   1,404.64x = 1,580,490.75
5. Step 5: Solve for x
   x = 1,580,490.75/1,404.64
6. Step 6: Final answer
   x = 1,125.19