Finding the Fourth Proportional to 1,039.91, 1,434.38 and 647.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,039.91 : 1,434.38 = 647.12 : x
2. Step 2: Convert to fraction form
   1,039.91/1,434.38 = 647.12/x
3. Step 3: Cross multiply
   1,039.91x = 1,434.38 × 647.12
4. Step 4: Simplify right side
   1,039.91x = 928,216.34
5. Step 5: Solve for x
   x = 928,216.34/1,039.91
6. Step 6: Final answer
   x = 892.60