Finding the Fourth Proportional to 1,405.03, 1,938.86 and 815.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.03 : 1,938.86 = 815.76 : x
2. Step 2: Convert to fraction form
   1,405.03/1,938.86 = 815.76/x
3. Step 3: Cross multiply
   1,405.03x = 1,938.86 × 815.76
4. Step 4: Simplify right side
   1,405.03x = 1,581,644.43
5. Step 5: Solve for x
   x = 1,581,644.43/1,405.03
6. Step 6: Final answer
   x = 1,125.70