Finding the Fourth Proportional to 1,405.51, 1,939.50 and 815.95

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.51 : 1,939.50 = 815.95 : x
2. Step 2: Convert to fraction form
   1,405.51/1,939.50 = 815.95/x
3. Step 3: Cross multiply
   1,405.51x = 1,939.50 × 815.95
4. Step 4: Simplify right side
   1,405.51x = 1,582,535.03
5. Step 5: Solve for x
   x = 1,582,535.03/1,405.51
6. Step 6: Final answer
   x = 1,125.95