Finding the Fourth Proportional to 1,320.91, 1,981.73 and 443.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,320.91 : 1,981.73 = 443.48 : x
2. Step 2: Convert to fraction form
   1,320.91/1,981.73 = 443.48/x
3. Step 3: Cross multiply
   1,320.91x = 1,981.73 × 443.48
4. Step 4: Simplify right side
   1,320.91x = 878,848.82
5. Step 5: Solve for x
   x = 878,848.82/1,320.91
6. Step 6: Final answer
   x = 665.34