Finding the Fourth Proportional to 1,665.53, 2,496.49 and 821.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.53 : 2,496.49 = 821.81 : x
2. Step 2: Convert to fraction form
   1,665.53/2,496.49 = 821.81/x
3. Step 3: Cross multiply
   1,665.53x = 2,496.49 × 821.81
4. Step 4: Simplify right side
   1,665.53x = 2,051,644.63
5. Step 5: Solve for x
   x = 2,051,644.63/1,665.53
6. Step 6: Final answer
   x = 1,231.83