Finding the Fourth Proportional to 1,320.82, 1,980.58 and 443.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,320.82 : 1,980.58 = 443.02 : x
2. Step 2: Convert to fraction form
   1,320.82/1,980.58 = 443.02/x
3. Step 3: Cross multiply
   1,320.82x = 1,980.58 × 443.02
4. Step 4: Simplify right side
   1,320.82x = 877,436.55
5. Step 5: Solve for x
   x = 877,436.55/1,320.82
6. Step 6: Final answer
   x = 664.31