Finding the Fourth Proportional to 1,039.64, 1,434.72 and 573.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,039.64 : 1,434.72 = 573.90 : x
2. Step 2: Convert to fraction form
   1,039.64/1,434.72 = 573.90/x
3. Step 3: Cross multiply
   1,039.64x = 1,434.72 × 573.90
4. Step 4: Simplify right side
   1,039.64x = 823,385.81
5. Step 5: Solve for x
   x = 823,385.81/1,039.64
6. Step 6: Final answer
   x = 791.99