Finding the Fourth Proportional to 1,642.77, 2,461.59 and 819.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,642.77 : 2,461.59 = 819.81 : x
2. Step 2: Convert to fraction form
   1,642.77/2,461.59 = 819.81/x
3. Step 3: Cross multiply
   1,642.77x = 2,461.59 × 819.81
4. Step 4: Simplify right side
   1,642.77x = 2,018,036.10
5. Step 5: Solve for x
   x = 2,018,036.10/1,642.77
6. Step 6: Final answer
   x = 1,228.43