Finding the Fourth Proportional to 1,405.47, 1,939.51 and 775.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.47 : 1,939.51 = 775.98 : x
2. Step 2: Convert to fraction form
   1,405.47/1,939.51 = 775.98/x
3. Step 3: Cross multiply
   1,405.47x = 1,939.51 × 775.98
4. Step 4: Simplify right side
   1,405.47x = 1,505,020.97
5. Step 5: Solve for x
   x = 1,505,020.97/1,405.47
6. Step 6: Final answer
   x = 1,070.83