Finding the Fourth Proportional to 1,289.82, 1,780.20 and 730.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,289.82 : 1,780.20 = 730.28 : x
2. Step 2: Convert to fraction form
   1,289.82/1,780.20 = 730.28/x
3. Step 3: Cross multiply
   1,289.82x = 1,780.20 × 730.28
4. Step 4: Simplify right side
   1,289.82x = 1,300,044.46
5. Step 5: Solve for x
   x = 1,300,044.46/1,289.82
6. Step 6: Final answer
   x = 1,007.93