Finding the Fourth Proportional to 1,320.57, 1,981.61 and 498.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,320.57 : 1,981.61 = 498.81 : x
2. Step 2: Convert to fraction form
   1,320.57/1,981.61 = 498.81/x
3. Step 3: Cross multiply
   1,320.57x = 1,981.61 × 498.81
4. Step 4: Simplify right side
   1,320.57x = 988,446.88
5. Step 5: Solve for x
   x = 988,446.88/1,320.57
6. Step 6: Final answer
   x = 748.50