Finding the Fourth Proportional to 1,405.55, 1,939.59 and 815.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.55 : 1,939.59 = 815.99 : x
2. Step 2: Convert to fraction form
   1,405.55/1,939.59 = 815.99/x
3. Step 3: Cross multiply
   1,405.55x = 1,939.59 × 815.99
4. Step 4: Simplify right side
   1,405.55x = 1,582,686.04
5. Step 5: Solve for x
   x = 1,582,686.04/1,405.55
6. Step 6: Final answer
   x = 1,126.03