Finding the Fourth Proportional to 1,405.63, 1,939.89 and 776.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.63 : 1,939.89 = 776.26 : x
2. Step 2: Convert to fraction form
   1,405.63/1,939.89 = 776.26/x
3. Step 3: Cross multiply
   1,405.63x = 1,939.89 × 776.26
4. Step 4: Simplify right side
   1,405.63x = 1,505,859.01
5. Step 5: Solve for x
   x = 1,505,859.01/1,405.63
6. Step 6: Final answer
   x = 1,071.31